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July 20 to July 26: This Week in Denver Weather History

July 20, 2025 Thornton Weather Leave a comment

This Week in Denver Weather History

Heavy rain events become more commonplace as we get further into Colorado’s monsoon season. Our look back at this week in Denver weather history contains many examples of the damage these fast-moving events can cause.

From the National Weather Service:

7-25

In 1934…a streak of 15 consecutive days of 90 degrees ranked 5th on the list of hot streaks. The record of 24 consecutive days was established in the summer of 2008.

13-5

In 2008…a streak of 24 consecutive days of 90 degrees shattered the previous record of 18 consecutive days established in 1901 and 1874. Ironically…no new single day record high temperatures were set in the month of July. In August however…a record of 104 degrees was set on the 1st…and another record of 103 degrees was set on the 2nd. In addition…a record low min of 70 degrees was set on August 2nd.

18-2

In 1987…a streak of 16 consecutive days of 90 degrees ranked 4th on the list of hot streaks. The record of 24 consecutive days was established in the summer of 2008.

19-23

In 2005…the high temperature climbed above 100 degrees on each of the 5 days with readings of 101 on the 19th…105 on the 20th…104 on the 21st…and 102 on both the 22nd and 23rd. A new record maximum temperature for the month of July of 105 degrees was set on the 20th…which also equaled the all-time record maximum for Denver of 105 degrees first set on August 8th in 1878. Daily maximum temperature records were set on each day…and the 5 day period equaled the record for the most consecutive days of 100 degrees or more first set from July 4th through 8th in 1989. The intense heat resulted in a high use of electricity for cooling purposes. The demand for electric power exceeded the supply and rolling black-outs… Each lasting about an hour…were scheduled across metro Denver during the afternoons and early evenings.

In 1898…an apparent thunderstorm produced sustained northwest winds to 45 mph with gusts to 51 mph.

In 1939…the high temperature reached 102 degrees in downtown Denver. This was the highest temperature recorded since August 8…1878…a period of 61 years…and the third highest temperature of record at the time. Six miles to the east… At Denver municipal airport…the maximum temperature reached 104 degrees. A dry period during mid-July…combined with low relative humidities…resulted in an unusually large number of forest fires in the mountains west of Denver.

In 1941…an afternoon thunderstorm caused two lightning deaths. The men were struck by lightning near the Denver airport.

In 1951…a thunderstorm wind gust to 54 mph was recorded at Stapleton Airport.

In 1965…heavy rain west of Denver damaged roads and bridges. Two bridges in Golden were washed out. Lightning in Denver caused some power failures and fires…mostly in the northeast section of the city. Heavy rain caused street flooding in the city of Denver. Hail as large as 1/2 inch in diameter and 0.40 inch of rain in 5 minutes were measured at Stapleton International Airport where precipitation totaled 1.09 inches. Lightning damaged a house in Littleton…and caused a power outage in Idaho Springs.

In 1973…lightning damage was reported west of Arvada.

In 1975…heavy rains caused flash flooding across metro Denver…resulting in the closing of several streets and damage to numerous homes and businesses. Hail 1/2 to 3/4 inch in diameter was reported.

In 1976…heavy thunderstorms caused flooding of streets in southeast Denver and western Arapahoe counties. A total of 3.35 inches of rain was measured at Kassler southwest of Littleton.

In 1978…a girl was injured by lightning at a country club southwest of Denver.

In 1984…heavy rain was reported just east of Buckley Field in Aurora where 1.15 inches fell in just 45 minutes.

In 1986…thunderstorms dumped heavy rain across metro Denver causing extensive street flooding…power outages…and basement flooding. The greatest recorded rainfall was 4.39 inches in Lakewood. In extreme northwest Denver…2.29 inches of rain fell in just 20 minutes. Arvada was drenched with 2.60 inches of rain…and over an inch fell in southeast Denver and adjacent sections of Aurora.

In 1990…heavy thunderstorm rains caused flash flooding in sections of Littleton where 1.20 inches of rain fell in less than 30 minutes. The deluge caused dry creek to jump its banks…causing damage to residential streets…curbs…and sidewalks. Nearly 100 vehicles were stranded for a time in fender-deep water when sewers and drainage ditches became choked with debris. The heavy runoff submerged many Littleton streets and intersections.

In 1992…strong thunderstorms moved slowly through east metro Denver…producing rainfall up to 2.50 inches in a short time. Weather spotters reported 0.75 to 1.00 inch of rain in less than 30 minutes. Many areas of southeast Denver were flooded…including I-25 where up to 6 feet of water filled some underpasses. Hail to 3/4 inch in diameter fell in Aurora.

In 1995…a tornado touched down briefly in an open field near Strasburg. Thunderstorm winds gusted to 58 mph at Centennial Airport.

In 1996…strong thunderstorm winds damaged the building of a telephone installation company in the city of Denver.

In 1998…the high temperature reached 100 degrees at Denver International Airport.

In 2006…heavy rainfall in the overland wildfire burn area caused minor flash flooding in Jamestown. The roads behind the Jamestown fire hall were washed out…when a culvert was blocked by debris. A rockslide was also reported in town.

In 2009…a severe thunderstorm produced damaging winds…large hail and very heavy rain across the western and southern suburbs of Denver. Widespread damage was observed in the cities of Arvada…Lakewood and Wheat Ridge. The intense straightline winds were the result of a wet microburst which downed hundreds of trees and snapped power poles. Wind gusts to 80 mph were reported along with hail up to 1 3/4 inches in diameter. The combination of wind and hail caused widespread damage to homes and vehicles. The damage claim estimates totaled 350 million dollars; about 32900 claims were filed for homes…while another 19500 claims were filed for vehicles. As many as 90000 homes and businesses were left without power. In some areas it took up to 3 days to completely restore electrical service. Minor injuries were reported from broken glass during the storm…but no one was hospitalized. The storm crippled the computers at the Colorado crime information center in Lakewood for nearly 3 hours. One weak tornado touched down near Parker but did no damage. In southern Weld County… Severe thunderstorms produced widespread damage over 150 square miles of farmland. In all…400 farms were directly impacted by severe weather. Damage to crops alone was estimated to 3 million dollars. At Denver International Airport…a peak wind gust to 48 mph was observed from the northeast. In addition…1.01 inches was measured at the airport.

In 2019…a severe thunderstorm produced a wind gust to 60 mph at Centennial Airport. A thunderstorms produced a flash flood in southern Jefferson and southwest Denver counties. The flooding was particularly bad on southbound I-25 near 6th Avenue. One woman was rescued by a passerby in Lakewood when floodwaters began pouring into her car near Casa Bonita. Standing water up to 3 feet deep was observed on other streets in Lakewood. A homeless woman drowned near West 12th Avenue and Miller Street when she was swept away in the floodwaters. Her body was recovered the following day.

20-23

In 1961…unusually cool weather for July resulted in several temperature records. Record minimum temperatures were set or equaled on each day with readings of 51…51…49… And 49 degrees. High temperature of only 64 degrees on the 21st was a record low maximum for the date.

20-25

In 1965…heavy showers and thunderstorms doused metro Denver with significant rain each day. Rainfall for the six days totaled 5.16 inches at Stapleton International Airport. Massive rainfall occurred on the 20th…21st…and 25th… Flooding streets and basements and causing streams to overflow. The heaviest rainfall…2.05 inches…at Stapleton International Airport occurred on the 25th.

Continue reading July 20 to July 26: This Week in Denver Weather History →

July 13 to July 19: This Week in Denver Weather History

July 13, 2025 Thornton Weather Leave a comment

This Week in Denver Weather History

Snow in July? Officially no however, it was on July 17, 1872 that a U.S. Army Signal Service weather observer reported snow in Denver. However since official record-keeping did not begin until 1882, it doesn’t count. Read more about that event and others from this week in Denver weather history below.

From the National Weather Service:

1-18

In 1874…a streak of 18 consecutive days of 90 degrees tied for second with another streak that was later set in the summer of 1901. The record of 24 consecutive days was established in the summer of 2008.

1-31

In 2012…it was the hottest July on record in Denver since weather records began in 1872. The average temperature for the month was 78.9 degrees which was 4.7 degrees above normal. There were 27 days in which the high temperature equaled or exceeded 90 degrees…which established a new record. There were also 7 days in which the temperature equaled or exceeded 100 degrees which tied the record set in 2005.

6-23

In 1901…a streak of 18 consecutive days of 90 degrees tied for second with another streak set in the summer of 1874. The record of 24 consecutive days was established in the summer of 2008.

7-25

In 1934…a streak of 15 consecutive days of 90 degrees ranked 5th on the list of hot streaks. The record of 24 consecutive days was established in the summer of 2008.

In 1902…west winds were sustained to 42 mph with gusts to 48 mph.

In 1910…an apparent dry microburst produced northeast winds sustained to 41 mph.

In 1961…hail as large as 1 inch in diameter was reported near Commerce City.

In 1982…a tornado touched down briefly south of Parker. No damage was reported.

In 1985…thunderstorms drenched the Highlands Ranch area of northern Douglas County with 1.50 inches of rain in just 30 minutes. Half an inch of rain fell in 15 minutes in Littleton.

In 1986…a lightning bolt struck a church steeple in Littleton…toppling it to the ground.

In 1989…thunderstorm winds blew down trees and bent a metal basketball fixture just north of Castle Rock in the surrey ridge area.

In 1993…1 inch diameter hail was measured in Lakewood.

In 1995…lightning struck and injured an assistant coach during a baseball game at Highlands Ranch south of Denver.

In 1996…3/4 inch diameter hail fell in Lochbuie with 1 1/2 inch hail measured in Brighton. Thunderstorm winds gusted to 69 mph at Bennett. The strong winds were responsible for flipping three semi-trailer trucks onto their sides along I-70…3 miles east of Bennett. A few cars were also overturned.

In 2001…heavy thunderstorm rain caused flash flooding over south metro Denver. Three inches of rain reportedly fell near the greenwood village police department in the span of 15 minutes. The heavy rain caused toll gate creek to overflow…flooding low lying areas along Parker road. Heavy rainfall also caused local flooding along streets near the Denver technology center. A severe thunderstorm dumped hail to 1 3/4 inches in diameter near Castle Rock.

In 2003…maximum temperature of 100 degrees was a record high for the date.

In 2009…severe thunderstorms produced wind gusts to 70 mph near Parker and Strasburg. At Denver International Airport…west-northwest winds gusted to 40 mph.

In 2011…severe thunderstorms produced extensive damage as they moved across the urban corridor. At Denver International Airport alone…large hail up to golfball size…very heavy rain and wind gusts to 59 mph caused substantial damage to 40 planes and stranded approximately 1500 passengers overnight. Frontier and United airlines were hardest hit as dozens of planes were taken out of service for repairs; forcing the cancellation of at least 220 flights over the next several days. Damage to the aircrafts alone was nearly five million dollars. In addition…83 cars in airport parking lots were damaged… Along with some police cars and maintenance vehicles. In Watkins…two people suffered minor injuries and 35 to 40 homes were damaged. As many as two hundred residents in a mobile home park were left homeless by the storm…forcing the red cross to open a shelter at Bennett high school. The trailer park contained 52 mobile homes…14 recreational vehicles…3 houses and a commercial building. Hailstones the size of softballs cratered the north sides of the mobile homes. Some farmers in the area said they lost as much as 85 percent of their total wheat crop. Power lines were also damaged which affected about 1200 customers in Watkins. The strong winds also flipped over a tractor- trailer rig on I-70 near Watkins Road. Insurance claims for the Watkins…Bennett and Brighton areas was estimated to be seventeen million dollars. The total damage estimate across the entire urban corridor…was near one hundred sixty five million dollars…and included 17200 automobile claims and 12600 homeowner claims. In addition…thunderstorms producing very heavy rainfall…caused flash flooding in the Four Mile Canyon burn scar west of Boulder. Three homes reportedly had water up to the windows with water flowing into structures at Fourmile Canyon road and gold run road. The heavy rain caused a 4-ft surge along Fourmile Creek through Orodell and into the entry of Boulder Creek. Several roads were affected which restricted access to the area. Roads were closed due to water and debris. Private bridges and drives were washed out and several residents were stranded and later rescued. Numerous cars were damaged in debris flows and several structures suffered flood damage but were not destroyed.

In 2019…a severe thunderstorm produced hail up to 1.0 inch in diameter in Broomfield…with 7/8 inch size hail reported in Arapahoe County near Buckley AFB.

13-5

In 1878…the temperature reached a high of 100 degrees in downtown Denver.

In 1906…a thunderstorm produced north winds sustained to 52 mph and 0.53 inch of rain in 10 minutes.

In 1912…a heavy thunderstorm cloudburst in the late afternoon combined with a similar storm to the south of the city to produce widespread flooding on Cherry Creek in downtown Denver…which resulted in two deaths and several injuries. The flooding was the worst since 1864 and covered around 3 square miles of lower downtown. Bridges along Cherry Creek were washed out and water lapped at the floor of the Broadway bridge over the South Platte River…causing authorities to declare it unsafe except for pedestrians. By nightfall… Union Depot was under 2 to 3 feet of water…and railroad and street car traffic was stalled. Those forced from their homes by the surging flood waters took refuge in the Denver auditorium. The flood waters caused great damage to the sewerage system…parkways…bridges and residences and commercial warehouses near Cherry Creek in the wholesale district. Flood damage was estimated at several million dollars. Heavy thunderstorm rainfall of 2.00 inches…of which nearly 1.75 inch fell in 30 minutes in central Denver… Was accompanied by severe thunderstorm winds sustained to 55 mph with gusts as high as 74 mph.

In 1933…thunderstorm rainfall was only 0.01 inch…but northwest winds sustained to 37 mph with gusts to 47 mph produced a dust storm for about 10 minutes during the late afternoon.

In 1967…heavy rain flooded areas of north and west metro Denver…and high water closed street intersections in the city. Crops were damaged…and 200 chickens drowned by flooding northwest of Denver where farm buildings and irrigation facilities were also damaged.

In 1969…a thunderstorm wind gust to 51 mph was recorded at Stapleton International Airport.

In 1975…heavy rains caused locally heavy flash flooding along Niver Creek south of Thornton and in other parts of north metro Denver. Over 40 thousand dollars in damage to public property was reported…and numerous homes and yards were damaged.

In 1986…thunderstorm winds blew down a power line in west- central Jefferson County. The storm…as it moved into Denver…snapped tree limbs and damaged a fence near Washington Park. Wind gusts in the area were estimated at 80 to 85 mph.

In 1990…thunderstorm wind gusts to 58 mph were recorded at Buckley Field in Aurora. No damage was reported. Winds gusted to 44 mph at Stapleton International Airport.

In 1993…a severe thunderstorm moved across southern sections of metro Denver. Dime size hail fell in Lakewood…and hail up to one inch diameter was measured at Cheery Creek Reservoir. Later in the afternoon…hail to one inch diameter fell in Golden and Arvada.

In 1994…hail to 1 1/4 inches in diameter fell north of Bennett.

In 1998…dry microburst winds estimated to 70 mph snapped tree branches up to 4 inches in diameter in Brighton where some road signs were twisted and blown down. At Denver International Airport…dry microburst winds gusted to 61 mph.

In 1995…thunderstorm winds gusted to 62 mph near Strasburg.

In 2001…a severe thunderstorm dumped hail to 3/4 inch in diameter in the foothills about 10 miles northwest of Golden.

In 2011…severe thunderstorms in the Denver metropolitan area produced very heavy rain…large hail and damaging winds. The strong winds toppled a few trees and the heavy rain caused street flooding and minor flash flooding. Several cars were stranded at the intersection of Santa Fe Drive and Oxford…and near Broadway and U.S. Highway 285. A 16-yr old teenager was seriously injured when he tried to retrieve a ball along the banks of West Toll Gate Creek. He was pulled from the swollen creek and died several days later. Hail up to one inch in diameter was reported around the area. The thunderstorms also produced frequent lightning. One strike sparked a fire at aspen academy…a private school in Greenwood Village. Most of the damage was confined to the roof and attic. In Englewood…a 40-ft tree was blown into a house and knocked down some power lines. At Denver International Airport…a severe thunderstorm produced sustained winds of 47 mph and a peak wind gust to 68 mph.

In 2019…a Denver man was killed and his wife injured after he was struck by lightning when they were hiking near the Bear Peak West Ridge Trail. The man was likely hit from a direct lightning strike to his upper body. His wife was not directly hit…but injured by the electrical current from the strike that hit her husband.

14-15

In 1985…thunderstorms dumped heavy rain and hail at numerous locations along the Front Range from Denver north. Some of the heaviest rain fell in northern and western suburbs of Denver. Up to 2.6 inches of rain drenched Arvada…and Thornton was soaked with 2 inches in 45 minutes. At least 5 homes in Arvada suffered extensive damage from water and mud…and many streets and basements were flooded. In southern Jefferson County…11 homes were struck by lightning.

Continue reading July 13 to July 19: This Week in Denver Weather History →

Weather History

July 6 to July 12: This Week in Denver Weather History

July 6, 2025 Thornton Weather Leave a comment

This Week in Denver Weather History

This week in Denver weather history shows record-setting heat, flooding rains, a few tornadoes and dangerous lightning. It must be July.

From the National Weather Service:

29-15

In 2000…the 29th marked the beginning of a near record hot streak for metro Denver. The high temperatures…as recorded at Denver International Airport…exceeded the 90 degree mark for 17 consecutive days from June 29th through July 15th. The record of 24 consecutive 90 degree or above days was set from July 13th through August 5th…2008.

1-18

1-31

4-8

In 1989…one of the most intense heat waves on record roasted metro Denver. The temperature reached 100 degrees or more on 5 consecutive days. The city had previously never recorded more than 2 straight 100-degree days since records began in 1872. Water and electricity usage reached all-time highs. The heat wave created extremely dry weather conditions…which contributed to a major forest fire in Boulder Canyon on July 9th. The temperature reached 103 degrees on the 8th…and the mercury climbed to 101 degrees on both the 4th and 5th…and to 102 degrees on both the 6th and 7th. The low temperature of 68 degrees on the 8th equaled the record high minimum for the date.

In 1876…the high temperature reached 101 degrees in downtown Denver.

In 1943…four people were injured by lightning in Denver during a severe early evening thunderstorm. At least two houses were set on fire by the lightning. One house had $1500 in damage and the other $1000.

In 1959…wind and lightning caused some damage in metro Denver. Wind gusts to 67 mph blew down power lines…signs… And trees. Lightning struck several transformers…leaving many areas without power.

In 1971…a microburst wind gust to 68 mph was recorded at Stapleton International Airport.

In 1973…the temperature reached a high of 103 degrees. This was the second consecutive day with a temperature of 100 degrees or more.

In 1984…a weak tornado moved through eastern Aurora. About 10 homes sustained minor damage to roofs; some sections of fence were thrown more than a block. Soft hail…an inch in diameter…fell over central Aurora…and 1.35 inches of rain fell in just 45 minutes…5 miles east of Buckley Field. Torrential rain and hail stopped traffic on I-225 in central Aurora for 15 minutes. Street flooding was widespread. A wind gust to 57 mph was recorded in southeast Aurora. A wind gust to 66 mph was reported at Front Range airport near Bennett. Northwest winds gusted to 44 mph at Stapleton International Airport where only 1/8 inch hail fell.

In 1986…one inch diameter hail fell near Conifer in the foothills west of Denver. The storm produced 1.50 inches of rain in an hour with a storm total of 2.15 inches. Nearby buffalo creek was drenched with 0.80 inch of rain in just 10 minutes.

In 1996…3/4 inch diameter hail fell in Bennett…east of Denver. Hail…as large as 1 1/2 inches in diameter… Damaged several vehicles in the parking lot of the Colorado speedway race track near Dacono north of Denver. Several trees were also damaged.

In 2001…a severe thunderstorm wind gust to 59 mph was recorded at Denver International Airport…along with small hail.

In 2009…hail up to 1 inch in diameter was observed near Longmont.

In 2010…heavy rain caused flash flooding near Interstate 70 at the Byers exit. Two feet of water was observed moving across the bottom of exit ramp. One car was washed into a tree but no one was injured. In addition…severe thunderstorms produced hail up to 1 1/2 inches in diameter near Franktown. At Denver International Airport…only 0.01 inches of rainfall was observed. A peak wind gust to 45 mph from the west was also recorded.

6-23

In 1901…a streak of 18 consecutive days of 90 degrees tied for second with another streak set in the summer of 1874. The record of 24 consecutive days was established in the summer of 2008.

In 1905…a thunderstorm produced sustained northeast winds to 40 mph…but only a trace of rain.

In 1933…heavy cloudbursts during the afternoon in the Idledale area and on Saw Mill Gulch caused flash flooding on Bear Creek resulting in 7 deaths. Flooding in Morrison was compounded when a wall of water as high as 15 feet swept down Mount Vernon Creek. The flooding caused extensive damage to the Bear Creek Canyon Highway.

In 1959…wind gusts to 45 mph at Stapleton Airport…but higher in other areas…damaged power lines and buildings and caused widespread minor damage from falling trees and broken limbs. A field house under construction at Adams County high school in Commerce City sustained severe damage.

In 1963…farm buildings east of Boulder were possibly damaged by a small tornado as there were unconfirmed reports of a funnel cloud in the area.

In 1967…a storm of cloudburst proportion caused damage from flooding in southwest and south Denver. Unofficial reports indicated rainfall of 2.00 inches in 30 minutes and more than 3.00 inches total from the storm. Streets and buildings were flooded by the heavy run-off. Hail in some areas contributed to flooding by blocking storm drains. Water accumulated 12 to 14 feet deep in several underpasses and some street intersections. A young woman drowned when she tried to cross a flooded street and was swept off her feet and trapped under a parked car. Water reached a depth of 5 feet in the street. Police rescued numerous stranded motorists. The roof and wall of a flat roofed store building collapsed under the weight of deep water on the roof. Cars were washed over curbs in many areas. In southwest metro Denver…100 to 150 homes were flooded. Hail caused damage in other areas of Denver and in Aurora. Wind toppled trees in several areas. Snowplows were called out to clear hail from some highways and runways at Stapleton International Airport. Lightning damaged trees and power lines and started a fire…which extensively damaged an automobile dealership. Thunderstorm rainfall totaled 0.83 inch at Stapleton International Airport.

In 1981…severe thunderstorms produced 3/4 inch hail over east Denver. About 1 1/2 inches of rain fell in Littleton. Thunderstorm winds gusted to 45 mph at Stapleton International Airport.

In 1983…tennis ball size hail fell about 5 miles north of Boulder; it was soft and caused no damage.

In 1987…a weak tornado touched down in Castle Rock. Several weak tornadoes were observed in the area. No damage was reported.

In 1988…lightning struck a sign at a bank near Louisville… Damaging it and causing a smoldering fire that resulted in smoke damage to the bank and an adjacent building. Heavy thunderstorm rain…accompanied by 1/2 inch diameter hail at Stapleton International Airport…briefly reduced the visibility to 1/4 mile. Rainfall totaled 1.41 inches… But 1.12 inches fell in 32 minutes.

In 2001…severe thunderstorms dumped large hail across north metro Denver. Hail to 1 3/4 inches in diameter fell near Erie with 7/8 inch hail measured in Thornton.

In 2004…a 9-year-old boy was struck by lightning while at a playground in Arvada. The umpire at a nearby baseball game…along with 2 passers-by…administrated CPR and resuscitated the boy who had quit breathing. The boy suffered first and second degree burns…but was released from the hospital in less than 24 hours. A dry microburst over Denver International Airport produced a peak wind gust to 61 mph.

In 2006…up to 3 inches of heavy thunderstorm rainfall in the Hayman wildfire burn area produced destructive flash flooding along west creek between the towns of Deckers and Westcreek in southwest Douglas County. Horse Creek…which drains into west creek…swelled from a normally small creek into a raging torrent…25 to 30 feet deep and 300 feet wide. The wall of water damaged or destroyed about 30 sections of a 5 mile stretch of State Highway 67…which parallels West Creek. Several homes were extensively damaged or destroyed. No injuries were reported…but several people had to be rescued…due to extensive damage to access roads and bridges in the area. Reconstruction was estimated at 13.3 million dollars.

In 2011…heavy rain associated with a wet microbursts produced over 3 inches of rain in 90 minutes across southeast Denver. In Denver…some underpasses were flooded with several feet of water which stranded motorists. As a result…the fire department conducted at least 10 water rescues. Some basements were inundated with up to 4 feet of water which caused extensive flood damage. The Platte Valley and Western Model Railroad Club’s model train display in Union Station was also damaged when 3 to 4 inches of mud and water spilled over some of the command and control systems. Several display modules and scenery pieces in a storage room were also damaged. The entire display spanned more than one thousand feet of track in a room that was once used as the jail at Union Station in the 1900s. Urban and small stream flooding was reported across the surrounding Denver suburbs. The storm left about 28000 Xcel customers without power when the storm snapped trees and power lines. In addition…heavy rain produced flash flooding in the Four Mile Canyon burn scar. Four debris slides occurred along Four Mile Canyon Drive…including one that was 100 yards wide and 4 feet deep. Several rockslides were reported in Lefthand and Boulder canyons. At Denver International Airport…1.04 inches of rain was observed. A peak wind gust of 46 mph from the southeast was also observed.

In 2012…heavy rain produced flash flooding in Boulder County near Jamestown. James canyon drive was closed after heavy rain washed out a section of the roadway. Heavy rain washed out a section of magnolia road…east-southeast of Nederland. Nearby…a trained spotter 4 miles east-northeast of Nederland… Measured 2.20 inches of rainfall. Flash flooding was also reported in the Fourmile burn area along Summerville road. In Dacono…in southern Weld County…the Colorado Department of Transportation used snowplows to clear standing water…up to 6 inches deep…from a section of Interstate 25. The interstate was closed in both directions for nearly two hours. South of the Denver…in central Douglas County…flash flooding was reported near Perry Park…where 2.5 inches of rain fell in one hour.

In 2014…an Arvada resident was injured by a nearby lightning strike while he recorded a video of a thunderstorm with his cell phone. He was standing in his garage…when a nearby lightning bolt knocked him out. He suffered overall body aches and had a ringing sensation in one of his ears. In Denver… lightning caused a power outage that affected the RTD light rail lines for a short time. In Castle Pines…lightning sparked a small attic fire. Severe thunderstorms produced large hail from 1 to 1 3/4 inches in diameter…along with damaging winds across Arapahoe…Boulder and Jefferson Counties including: northwest Arvada…Littleton and Louisville. Flash flooding was reported near Evergreen in central Jefferson County. Heavy rain…up to 2 inches in one hour…flooded several residences and washed out several bridges along Forest Estate Road. Heavy rainfall also produced street flooding in Denver along with some basement flooding. The strong winds…estimated to 60 mph…downed trees and power lines in southwest Littleton. At Denver International Airport…0.15 inches of rainfall was observed along with a peak wind gust to 42 mph from the southeast.

In 2020…a thunderstorm produced a peak wind gust to 63 mph near Bennett.

Continue reading July 6 to July 12: This Week in Denver Weather History →

Weather History

June 29 to July 5: This Week in Denver Weather History

June 29, 2025 Thornton Weather Leave a comment

This Week in Denver Weather History

The dog days of summer have begun to settle in and severe weather starts to become just a little bit less common. While the history books for the week still mention hail and tornadoes, we also see flooding rains, record setting heat and wildfires.

From the National Weather Service:

In 1874…eight different fires in mountain forests were visible from the city. All of the fires were extensive… And the volume of smoke from each was immense. Three of these fires had been burning from the 18th with varied intensity.

In 1911…an apparent dry microburst produced sustained winds to 45 mph.

In 1960…a strong gust of wind blew a small foreign sedan off the highway near Brighton…injuring the driver. East winds gusted to 40 mph at Stapleton Airport.

In 1961…thunderstorm winds estimated as high as 40 to 50 mph occurred over southeast Denver. No significant damage was reported.

In 1962…heavy rain and small hail caused some flooding in southwest Denver.

In 1995…upslope cloudiness with rain and fog cooled temperatures to record levels. Low temperature of 47 degrees equaled the record for the date. High temperature of only 54 degrees set a new record low maximum for the date. Rainfall totaled 0.90 inch at Denver International Airport and 0.41 inch at the site of the former Stapleton International Airport.

In 2003…a severe thunderstorm in Parker produced hail to 1 inch in diameter.

In 2011…two airmen from the Colorado National Guard suffered minor injuries when they were struck by lightning. They were hit while on duty at a flight line at Buckley Air Force Base. At Denver International Airport…a microburst produced a peak wind gust to 72 mph.

In 2022…a severe thunderstorm produced an isolated but intense microburst with a peak wind gust of 74 mph east of Centennial near Smoky Hill. At Denver International Airport…a peak gust to 34 mph was observed from the northwest. Blowing dust briefly reduced the visibility to one half of a mile…along with 0.05 inch rainfall.

29-2

In 1990…almost a year to date after the record breaking heat in early July 1989…the third longest heat wave in Denver history started. From June 29th through July 2nd the temperature reached 100 degrees or more on four consecutive days. The highest reading of 102 degrees occurred on the 29th…30th…and 1st. Combined with the 102 degree reading on June 27th this would have been the longest heat wave on record…but the temperature climbed to only 98 degrees on June 28th.

29-15

On 2000…the 29th marked the beginning of a near record hot streak for metro Denver. The high temperatures…as recorded at Denver International Airport…exceeded the 90 degree mark for 17 consecutive days from June 29th through July 15th. The record of 24 consecutive 90 degree or above days was set from July 13th through August 5th…2008.

In 1879…dense smoke from mountain forest fires covered the city and obscured the sun as it set behind the mountains.

In 1900…a thunderstorm produced northwest winds to 44 mph with gusts to 58 mph…but only a trace of rain.

In 1917…north winds were sustained to 47 mph with gusts to 52 mph.

In 1942…a strong thunderstorm produced hail and heavy rainfall in south Denver. Leaves were stripped from trees and heavy rain caused street flooding which halted traffic. Hail of unknown size reached a depth of 9 inches on the ground.

In 1965…funnel clouds were observed to the south of Stapleton International Airport and in Jefferson County…15 miles southwest of the airport. Later…a tornado touched down briefly 1 mile east of Littleton…causing only minor damage. Another tornado was observed 12 miles southwest of Stapleton International Airport in Jefferson County. Hail to 3/4 inch in diameter fell in the bear valley area…12 miles south- southwest of Stapleton International Airport. Yet another tornado was sighted 10 miles northwest of the airport. Cloudbursts accompanied by hail battered areas of Arapahoe and Adams counties east of Denver…damaging ripening grain fields. At Lafayette…3.50 inches of rain fell in 30 minutes…causing some flooding.

In 1982…numerous funnel clouds were observed over southwest metro Denver. Only one funnel touched down near the intersection of Jewell and Kipling. The tornado was on the ground for about 5 minutes and caused no damage except for uprooting some trees. In addition…thunderstorms produced heavy rain and hail in the foothills west of Denver. Over an inch of rain fell in a short time near Idaho Springs… Causing Clear Creek to overflow its banks and flood a few low lying areas of the town. A few people were evacuated… And water and mud entered several stores. The heavy rain also washed out several roads. Hail piled up to a depth of 3 to 4 inches near Idaho Springs. Hail to 3/4 inch was reported at many places across metro Denver including Stapleton International Airport. Lightning struck a chemistry building on the University of Colorado campus in Boulder and started a small fire. Thunderstorm wind gusts to 60 mph were reported near Brighton.

In 1984…heavy rain caused some street and basement flooding in Littleton. One location received 1.56 inches of rain in 75 minutes.

In 1987…a weak tornado near Watkins stayed on the ground for 5 minutes.

In 1990…a small twister touched down in an open field just north of the Rocky Mountain Arsenal. No damage was reported.

In 1998…hail as large as 1 inch in diameter fell near Evergreen.

In 2005…a severe thunderstorm produced hail as large as 3/4 inch near Roggen. The hail destroyed a wheat field.

In 2006…the temperature reached a high of 98 degrees at Denver International Airport. This marked the 19th day in June with a maximum temperature of 90 degrees or more setting a new all-time record for the month.

In 2011…very strong thunderstorm winds were also observed across portions of the urban corridor. A peak wind gust to 65 mph was recorded…2 miles northeast of Boulder with a gust to 63 mph at Front Range airport at Watkins and 7 miles southeast of Denver International Airport. The peak wind gust measured at Denver International Airport itself was 45 mph. A severe thunderstorm also produced one inch in diameter hail 2 miles south-southeast of Parker. In addition…a lightning strike destroyed a home in north Denver.

In 2019…eight hikers were injured by a nearby lightning strike at the Devil Head Lookout…west of Perry Park in Douglas County. Five hikers were able to walk out unassisted…while two other required assistance. Most complained of having tingling sensations…while two suffered from minor burns. The eighth victim suffered critical injuries and had to be carried out by stretcher and taken to a nearby hospital.

In 2023…a total of 5.35 inches of rain fell through the month of June…establishing the all time record for Denver. The previous record was 4.96 inches set 141 years earlier in 1882.

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In 1873…heavy rainfall overnight totaled 1.42 inches. Mountain peaks to the southwest of the city were covered with fresh snow on the morning of the 1st.

Continue reading June 29 to July 5: This Week in Denver Weather History →

Weather History

June 22 to June 28: This Week in Denver Weather History

June 22, 2025 Thornton Weather Leave a comment

This Week in Denver Weather History

Stormy skies are common this time of year as we see in our look back at this week in Denver weather history. Dangerous lightning, damaging hail and wind, and of course tornadoes have made their appearances.

From the National Weather Service:

21-22

In 1941…strong thunderstorms produced cloudbursts of rain in Boulder County…starting during the late evening of the 21st and continuing overnight. The heavy rains over the Boulder Creek…Left Hand Creek…and south St Vrain River basins produced flooding in already swollen streams and turned dry gulches into raging torrents. The force of the floodwaters swept a man from the arms of his wife to his death…severely damaged canyon homes and swept others away… And hurtled a car down a steep embankment after the driver narrowly escaped. West of Boulder…the Boulder Canyon highway was littered with rocks and debris and collapsed when two culverts were washed away. The flood waters washed much debris down four mile canyon…damaging the road near the creek bed. A bridge over dry creek just south of Niwot was completely washed away.

In 1964…scattered hail and rain caused property damage and local flooding in Boulder.

In 1989…an unseasonably cold weather system produced strong winds over much of metro Denver and snowfall in the foothills as low as 7500 feet elevation. One to 6 inches of snow fell in the foothills west of Denver with 15 inches reported on the summit of Mount Evans. Six inches of snow were measured at Conifer. Rainfall totaled only 0.09 inch at Stapleton International Airport where northwest winds gusted to 29 mph on the 21st.

In 1872…small sandstorms…frequently seen on the prairie… Occasionally passed through the city.

In 1983…3/4 inch hail was observed at Deckers…and a thunderstorm produced wind gusts to 55 mph at Littleton.

In 1988…a tornado was spotted one mile east of Brighton; it remained on the ground for about 6 minutes…but did no reportable damage. Lightning damaged a home near Castle Rock.

In 1991…thunderstorms produced golf ball size hail in Lafayette. The strongest storms occurred north of metro Denver.

In 1992…nickel size hail was reported just east of Parker.

In 1995…large hail 3/4 to 1 3/4 inches in diameter fell in Castle Rock where a funnel cloud was sighted. Hail 3/4 inch to 1 inch in diameter fell in south Denver and Aurora. A funnel cloud was also sighted over Chatfield Reservoir. In Bennett…very strong dry microburst winds of unknown speeds ripped a 14- by 48-foot metal roof off of a barn. The roof was tossed approximately 250 yards. A few 150- pound railroad ties were moved 10 to 15 feet.

In 1997…a tornado touched down near the Adams County fairgrounds northeast of Denver…uprooting several trees and damaging a car. A dry microburst produced a brief wind gust to 69 mph at Jefferson County Airport. A small brief tornado was sighted near Hudson…but did no reported damage.

In 1998…3/4 inch hail fell near Hudson.

In 1999…thunderstorm winds gusted to 63 mph at Denver International Airport.

In 2003…hail as large as 2 inches in diameter was measured in Fort Lupton with 3/4 inch hail in Erie and near Boulder.

In 2006…a small tornado (f0) touched down near Franktown… But caused no damage.

In 2008…strong winds from dry microbursts developed over parts of southern Weld and western Arapahoe counties. A peak gust of 60 mph was observed in Centennial. Near Frederick…strong winds snapped 3 power poles and sparked a small grassfire near State Highway 52 and interstate 25. At Denver International Airport…a peak gust of 31 mph was observed.

In 2009…hail up to 2 inches in diameter was observed near crescent in Boulder County.

In 2023…an tornado touched down just south of CO-470 in Highlands Ranch and lifted just west of I-25 near Lone Tree in Douglas County. Most of the damage was EF0 but there were some pockets of EF1 damage; it was on the ground for 26 minutes. The severe thunderstorm also produced large hail up to 2 1/2 inches in diameter. The tornado track was from 2 miles west of Highlands Ranch to 2 miles north-northeast of Surrey Ridge with a path length of 8.36 miles. The maximum width of the tornado was approximately 50 yards There were no injuries.

22-26

In 2012…the maximum temperature exceeded 100 degrees for five consecutive days. Two of the high temperatures on the 25th and 26th peaked at 105 degrees…which set the all-time record for the month of June and tied the all-time maximum temperature for Denver.

In 1874…a thunderstorm pelted the city with hail and brief heavy rain. Rainfall was 0.30 inch in 10 minutes. Total rainfall was 0.36 inch for the day. Hail to 1/4 inch in diameter destroyed the strawberry fields near the limits of the city. The thunderstorm dropped the temperature from 93 degrees to 80 degrees in 5 minutes.

In 1887…north winds were sustained to 42 mph.

In 1954…the temperature climbed to a high of 102 degrees… Setting a record for the date.

In 1962…lightning struck and injured a man near Buffalo… Southwest of Denver…while he was riding in the back of a pick-up truck. He suffered multiple bruises…cuts…and shock.

In 1965…an apparent tornado was reported 18 miles east of Denver. No damage was reported.

In 1975…hail up to 3/4 inch in diameter fell at Stapleton International Airport and over other parts of metro Denver. Four funnel clouds were sighted: 10 miles northeast of Denver…south of Boulder…southeast of Boulder…and south of Aurora.

In 1976…heavy rain and eroding water collapsed a retaining wall in Thornton.

In 1981…a thunderstorm produced wind gusts to 60 mph in Littleton.

In 1982…two separate bolts of lightning injured three men in southwest Denver. Two buildings were slightly damaged.

In 1987…severe thunderstorms produced large hail across metro Denver. Golf ball size hail fell in Littleton…near Morrison…and in southeast Aurora with 1 1/2 inch hail recorded in south Lakewood and 1 inch hail reported in Littleton…Arvada…and at Cherry Creek dam. Two funnel clouds were sighted 20 miles southwest of Stapleton International Airport.

In 1993…non-convective high winds developed along the Front Range foothills. Wind gusts to 70 mph were common near the foothills with numerous tree limbs broken by the winds. North winds gusting to 36 mph were recorded at Stapleton International Airport.

In 1999…hail as large as 1 inch in diameter was measured in the city of Denver with 3/4 inch hail in Littleton.

In 2001…a severe thunderstorm produced large hail in south metro Denver. Hail as large as 1 1/2 inch in diameter fell in Littleton with 1 1/4 inch hail near Sheridan.

In 2009…hail up to 1 inch in diameter was observed near Parker. At Denver International Airport…a total of 1.64 inches was measured in a 24-hr period…setting a new record for the date.

In 2014…severe thunderstorms produced large hail near Commerce City and Fort Lupton. The hail sizes ranged from 1 to 1 1/2 inches in diameter.

In 2016…a severe thunderstorm produced a peak wind gust to 60 mph near Strasburg.

Continue reading June 22 to June 28: This Week in Denver Weather History →

Weather History

June 15 to June 21: This Week in Denver Weather History

June 15, 2025 Thornton Weather Leave a comment

Our look back at this week in Denver weather history is dominated by some relatively common late spring / early summer weather events, especially lightning, hail and wildfires.

From the National Weather Service:

12-17

In 2000…two large wildfires developed in the Front Range foothills as careless campers and very dry conditions proved to be a dangerous combination. Strong winds gusting in excess of 60 mph on the 13th fanned the flames… Spreading both wildfires out of control. Winds gusted to 78 mph atop Niwot Ridge near the Continental Divide west of Boulder. The Hi Meadows wildfire…about 35 miles southwest of Denver…consumed nearly 11 thousand acres and 80 structures…mostly high priced homes. The Bobcat wildfire…located about 12 miles southwest of Fort Collins… Consumed nearly 11 thousand acres and 22 structures. Late on the 16th…a strong cold front moved south over the great plains into northeastern Colorado. Low level upslope conditions developed in the wake of the front…producing 2 to 4 inches of snowfall overnight at elevations above 8 thousand feet. Firefighters were able to contain both fires shortly thereafter.

In 1907…south winds were sustained to 40 mph. The winds were strong all day.

In 1908…the hail storm was unusually severe. Heavy clouds moved over the city from the north and northwest…and by late morning the weather had become very threatening. Heavy rain with intermittent hail from pea to 3/4 inch in diameter fell near noon. The fall of rain and hail totaled 0.68 inch of precipitation with 0.35 inch in just 5 minutes. The temperature fell from 71 degrees to 51 degrees during the storm. The hail did considerable damage to trees…gardens…and hot houses. On sidewalks with northern exposures…the hail ranged in depth from 2 to 6 inches. West winds were sustained to 29 mph during the storm.

In 1956…strong southeast winds raked metro Denver all day. Sustained winds at 44 mph with gusts as high as 61 mph were recorded at Stapleton Airport where blowing dust briefly reduced the visibility to 2 miles.

In 1984…golf ball size hail pelted southern and central Aurora. Rainfall of 2.06 inches over central Aurora in just over an hour produced local street flooding.

In 1987…golf ball size hail fell in the southern part of Lakewood.

In 1988…several tornadoes developed across metro Denver. One tornado touched down just northeast of the rocky mountain arsenal. The twister moved very slowly and did no damage…except to demolish a small electrical substation… Even though it was on the ground for nearly 30 minutes. Later…another tornado was sighted east of Brighton about 2 miles north of Barr Lake. An f2 tornado cut a swath through northeast Denver. The main path went through a thickly wooded area for about 6 blocks and uprooted about 500 city owned trees…many of them large elms 75 to 100 years old. Hundreds of privately owned trees were also sucked from the ground by the slow moving twister…which was filmed by a news team in a helicopter as it uprooted trees. The replacement cost to the city owned trees was estimated at 1.5 million dollars. The twister did little damage to buildings. Some homes suffered roof and chimney damage…a gas main was ruptured…and some cars were damaged by falling trees. The uprooted trees also caused curb and sidewalk damage and cut some electrical wires. The funnel cloud passed close to Stapleton International Airport. Aircraft operations were shut down…and the tower was evacuated. The tornado was on the ground for almost 25 minutes. An f3 tornado cut an erratic path through south Denver for about 25 minutes…causing extensive damage in at least 3 areas. The twister damaged about 85 buildings… 20 severely; the total loss was estimated at 5 to 10 million dollars. Many cars were severely damaged; at least 15 vehicles were overturned. One trailer was lifted onto the top of a building that had just been unroofed; numerous antique cars inside the building were damaged. A Ford Bronco was blown over a church…and landed 100 yards away. A metal storage shed was deposited far above the ground in some power lines. The tornado uprooted many trees on a golf course. No one was seriously hurt…although seven people suffered minor injuries from flying debris. A golfer was thrown 40 feet…but was not hurt; a man clinging to a telephone pole was unscathed…but lost both shoes…a sock…and buttons off his shirt. A woman holding a baby was sucked through a broken convenience store window… But was unhurt. A dog…tethered to the ground by its leash… Was suspended in the air by the twister. Uprooted trees crushed cars and damaged curbs and sidewalks. People in downtown Denver could see three tornadoes occurring simultaneously. Hail as large as 1 3/8 inches in diameter fell in extreme southeast Aurora.

In 1997…a tornado touched down briefly at the Colorado National Speedway near Dacono north of Denver. The tornado ripped through the south grandstand causing at least 50 thousand dollars in damage to a shed…kiosk… Bleachers…and several concession stands.

In 2004…a tornado touched down briefly near Castle Rock and blew the roof off a machine shop. A tornado near Elizabeth destroyed a barn and caused roof damage to a home. Two other barns on nearby properties were damaged extensively. The twister also caused widespread tree damage in the area. A tornado also touched down near Bennett and Strasburg…but did no damage.

In 2009…thunderstorm winds knocked a tree on to two vehicles in Boulder. One of the drivers was injured when the tree smashed into the windshield of her car.

In 2012…a severe thunderstorm produced hail from quarter to half dollar size near Littleton and Highlands Ranch. A weak short lived tornado (ef0) also touched down near Bennett.

15-16

In 1963…heavy rain and hail ravaged metro Denver. In southeast Denver…heavy rain flooded homes and streets. Hail to a depth of 4 inches on the ground stripped trees and plants and drifted to depths of 3 to 4 feet in some areas. Flood waters on the valley highway were 19 feet deep in places…trapping many cars. Many creeks were running over their banks. On the 15th…the main thunderstorm cell passed over south Denver…dumping as much as 4 inches of rain in 90 minutes. Precipitation at Stapleton Airport totaled 0.91 inch on the 15th and 1.31 inches on the 16th. A funnel cloud was sighted briefly 4 miles to the south-southeast of Stapleton Airport on the 15th. Damage from hail and flooding amounted to near a million dollars.

15-17

In 2021…the temperature in Denver reached 100 degrees for three consecutive days: 101…100…100 respectively. Each established a new record high for the day. It was also the earliest occurrence of such a streak. A record high minimum of 68 also occurred on the 17th.

In 1950…very heavy rain and hail storms in southwest Denver caused an estimated 750 thousand dollars in hail and flood damage. Thunderstorms produced 2.06 inches of rain at Stapleton Airport with 2.23 inches of rain measured in downtown Denver.

In 1965…a tornado…15 miles south-southeast of Denver… Touched down and damaged two houses in northern Douglas County. Three golfers at a country club and a women who lived north of Castle Rock were injured by falling structures.

In 1983…a microburst wind gust to 54 mph was recorded at Stapleton International Airport.

In 1984…a tornado touched down briefly in Parker. No damage was reported.

In 1986…lightning injured 5 people just north of the Denver city limits in Adams County. The victims were members of a drum and bugle corps and were standing near a metal scaffold. Heavy rain from the storm also caused street flooding in the metro area.

In 1991…hail to golf ball size fell at Conifer.

In 1992…a rare mid-June high wind event wreaked havoc over metro Denver when a pacific cold front moved across the Rocky Mountains. Strong winds at speeds of 40 to 50 mph were common along the Front Range foothills. Winds reaching 107 mph in the foothills west of Denver and 79 mph at Longmont…caused damage ranging from trees being toppled to large trucks being rolled over. Strong winds estimated at 75 mph rolled a 35-foot truck carrying building supplies on U.S. Highway 36 north of Boulder. The truck driver and a passenger as well as the driver of another car were slightly injured. The winds downed power lines. The gambling towns of central city and Blackhawk were without power for a couple of hours. West winds reached 43 mph at Stapleton International Airport.

In 1996…a small tornado touched down in the foothills southwest of Boulder near Pinecliffe…knocking down 50 to 100 large pine trees. A house nearby sustained damage when shingles were ripped from the roof. The tornado also picked up a 17-foot sailboat with attached trailer and carried it 25 feet into a nearby tree. In addition… Thunderstorm wind gusts to 46 mph were measured at Denver International Airport.

In 2004…hail as large as 1 inch in diameter fell near Castle Rock. Hail to 3/4 inch was measured near Bennett.

In 2005…severe thunderstorms produced hail as large as 1 inch in diameter in Centennial.

In 2011…severe thunderstorms produced and damaging across parts of metropolitan Denver. In Lakewood…a tree blew down and landed on at least five cars. At Centennial Airport…a section of a roof on a hangar was ripped off the strong winds. A peak wind gust of 46 mph was recorded at Centennial Airport and Denver International Airport in the evening.

In 2022…severe thunderstorms produced large hail across parts of Boulder and Weld counties. The hail ranged from 1 to 1 1/2 inches at Allenspark…Ft. Lupton…Hudson and Lochbuie.

Continue reading June 15 to June 21: This Week in Denver Weather History →

Weather History

June 8 to June 14: This Week in Denver Weather History

June 8, 2025 Thornton Weather Leave a comment

June is the month of the year when Colorado receives the majority of its severe weather and that is seen in our look back at this week in Denver weather history. Also notable are several historical wildfires, including the Hayman blaze.

From the National Weather Service:

1-30

In 2012…it was the hottest June in Denver since weather records began back in 1872. The average temperature for the month was 75.0 degrees which was 7.6 degrees above normal. There were a total of seventeen 90 degree days in the month of June. The highlight of record setting month was a stretch of five consecutive 100 degree days from the 22nd to the 26th. This was only the third time in Denver weather history in which this happened. Two of the high temperatures during the stretch peaked at 105 degrees… Which set the all-time record for the month of June and tied the all-time maximum temperature for Denver.

7-9

In 1979…rain…at times with thunder on the 7th…fell almost continuously through the morning of the 9th. Rainfall totaled 2.28 inches at Stapleton International Airport over the 3 days. High temperature of only 49 degrees on the 8th was a record low maximum for the date.

In 1873…lightning struck and killed one man and damaged several houses. The thunderstorms produced heavy rain in the city…which caused a great deal of water damage. At 2:40 pm heavy rain began and by 4:00 pm 1.40 inches of rain had fallen. Two buildings under construction…with a projected cost of 100 thousand dollars…were badly damaged. The stone foundation and some of the brick walls were carried away by the storm waters. Many basements were flooded…which damaged goods stored there. Rainfall totaled 1.71 inches.

In 1964…lightning struck a building in Boulder…starting a fire and burning two workmen.

In 1968…a severe thunderstorm flooded streets…and hail- damaged trees and gardens…including flowers at a large commercial nursery in Boulder.

In 1969…severe hail damaged property…trees…and gardens… And heavy rain flooded streets and underpasses throughout metro Denver. The heaviest amounts of rain fell in south Denver and Englewood where unofficial totals of 5 to 6 inches were reported. Hail accumulated to 3 or 4 inches on the level and 2 to 3 feet deep in drifts. Mud…debris…and hail carried by the heavy runoff clogged drains and increased the amount of flooding. About 40 cars and a large truck were inundated at an underpass on an interstate highway…and several more were inundated or buried in mud in other areas. A large number of basements were flooded. Streets and highways were heavily damaged in some areas. Rainfall totaled 1.66 inches at Stapleton International Airport.

In 1974…a late spring storm dumped 1.79 inches of rain over metro Denver…causing local flooding. Strong gusty winds accompanied the storm…downing some power and telephone lines. Northwest winds gusted to 56 mph at Stapleton International Airport where a trace of snow fell. Measurable snowfall occurred at mid-day over Aurora and suburban areas to the south of Denver. A number of people were temporarily stranded in the mountains west of Denver where heavy snow fell. Low temperature of 37 degrees equaled the record minimum for the date. High temperature of 50 degrees was a record low maximum for the date.

In 1986…strong thunderstorm winds blew down a garage wall in Littleton and caused minor roof damage to several homes. Boats were overturned and damaged at a sporting goods store nearby. As the storm moved northeast it produced a small tornado…which touched down in extreme southeast Denver and moved northeast into Aurora. The twister did most of its estimated one million dollars damage shortly after touching down in an apartment complex and a shopping center. Two apartments were completely unroofed; wooden chimney facings were demolished and metal pipes were twisted. Many trees up to 25 feet high in the complex were uprooted. Doors were ripped off their hinges…and several parked cars were damaged. In the shopping center…a wall of a building was stripped of its brick facing…and many windows were broken. The twister picked up an aluminum rowboat…carried it 250 feet over some apartments…and deposited it in a vacant storefront. Around 200 cars were damaged in the shopping center. Benches bolted to the pavement were knocked over. Six people suffered minor injuries caused by flying debris. After hitting the shopping center and apartment complex…the tornado moved northeast into a residential area where it toppled some trees and damaged several fences. The same storm later produced 3 separate small tornadoes 5 miles north of Watkins.

In 1987…torrential rain produced extensive flooding across metro Denver. I-25 was closed for a time through central Denver…and a trailer park in Lakewood was partially evacuated due to high water. Several streets in Boulder were closed due to flooding. There was extensive basement flooding and water damage in Lakewood and southeast Denver. Lightning hit a power plant in Denver that supplied electricity to storm drain pumps which exacerbated street flooding in some areas. Rainfall from the thunderstorms totaled 1 1/2 to 2 inches at many locations in Lakewood central and northeast Denver. The heaviest amount of reported rain was in Lakewood where 2 1/4 inches fell in just 2 hours. At Stapleton International Airport…1.62 inches of rain fell in an hour. Rainfall totaled 1.76 inches for the day.

In 1988…a tornado touched down 15 miles northwest of Bennett and stayed on the ground for 15 minutes. The twister was observed by national weather service personnel at Stapleton International Airport. No damage was reported.

In 1989…a small tornado hit a neighborhood in southeast Aurora. The twister hit a dozen homes…blowing out windows…knocking down fences…and partially unroofing one house. About a half dozen trees were felled. A basketball pole was severely bent. The tornado was on the ground for about 2 minutes. Total damage was estimated at 50 thousand dollars. Lightning also struck a home in Parker…causing 25 hundred dollars damage.

In 1992…very heavy thunderstorm rains drenched southwestern weld and eastern Boulder counties. Measured rainfalls of over 2 inches an hour caused St. Vrain Creek to rise 2 feet out of its banks. Boulder creek was also out of its banks along U.S. Highway 287. I-25 flooded with 3 to 5 feet of water along a 9-mile stretch from the Erie exit to the Frederick exit. The highway was closed for over 6 hours while snowplow drivers and farmers with tractors rescued stranded motorists. Water rose into homes along south Boulder road in Lafayette. Several small county roads were washed out along the Boulder County/Weld County line. An off-duty National Weather Service employee measured 3/4 inch hail in Thornton. Several locations north of Denver had small hail up to 6 inches deep. A funnel cloud was spotted 18 miles northeast of Stapleton International Airport.

In 1998…severe thunderstorms dropped large hail across metro Denver. Hail as large as 1 3/4 inches in diameter fell near columbine in Jefferson County. One inch diameter hail fell in Aurora and Littleton with 7/8 inch hail in Arvada and 3/4 inch hail at Centennial Airport… Near greenwood village…and in Parker.

In 2004…heavy rain and large hail caused flooding and flash flooding across northeast Jefferson County. In Golden… Heavy rains triggered a small mudslide on U.S. Highway 6 near the intersection of Colorado highway 119. Automated rain gages in the area registered 2 to 3 inches of rainfall in one hour. Near the Colorado Mills mall…numerous streets were inundated with 1 to 3 feet of water and hail…which stranded several vehicles…including a fire engine. About 30 basements were flooded in Golden and Lakewood. Many windows in both homes and cars were shattered by the large hail. Hail as large as 1.5 inches in diameter was measured in and near Golden with hail to nearly an inch in diameter a few miles north of Evergreen.

In 2007…the low temperature in Denver bottomed out at 31 degrees…which established a new record minimum for the date. It also became the latest date of the last freeze in Denver.

In 2014…in Aurora…a tornado touched down near the Blackstone Country Club…it lifted some golf carts and flipped an empty construction trailer. One of the carts was thrown on top of a caddy walking nearby; he was taken to a hospital with minor injuries. It was assigned an EF-1 rating. In Englewood…lightning struck a tree which damaged two nearby homes and a truck. Large hail…from 1 to 1 1/2 inches in diameter…was reported near Buckley Air Force Base and near Castle Rock. Other short lived tornadoes touched down near Byers and Roggen.

In 2019…severe thunderstorms erupted around metro Denver late in the afternoon and spread eastward onto the plains. The largest hail fell around Castle Rock…where hail up to 2 1/2 inches was reported. Elsewhere…the hail ranged from 1 to 1 1/2 inches.

In 1900…an apparent cold front produced north winds to 42 mph with gusts to 47 mph.

In 1923…heavy rainfall totaled 2.18 inches in downtown Denver…where northwest winds were sustained to 27 mph. Heavy rain also fell in Boulder…causing flooding on Boulder and south Boulder creeks.

In 1939…post-frontal sustained northwest winds to 35 mph produced some blowing dust…which reduced the visibility to one mile at times during the afternoon. Dusty conditions prevailed into the early evening. The airport station reported a maximum wind of 56 mph. A few minor injuries and some damage resulted. A few trees were uprooted…some fruit was blown from trees…and a section of power lines was blown down.

In 1959…dry thunderstorm winds…estimated to near 70 mph… Toppled a 40-foot-high poplar tree…which was 4 to 5 inches in diameter…near Cherry Creek dam. The Colorado state patrol reported a possible tornado 1 mile south of the dam.

In 1960…strong gusty winds tore the roofs from 2 patios in Aurora. One of the roofs was blown over a house and landed on a car damaging its top. A house trailer was also overturned. Other minor damage was reported to roofs… Windows…and trees in Aurora. A thunderstorm wind gust to 43 mph was recorded at Stapleton Airport.

In 1963…golf ball size hail fell at Cheery Creek Reservoir.

In 1967…a small tornado damaged trees and a dwelling in south Denver. The storm touched down at the intersection of 1st avenue and Harrison Street and moved northeast to the intersection of 3rd avenue and Albion Street. Damage included 3 small roofs removed…15-20 large trees uprooted…one car overturned and thrown against a house… Plus other minor damage. A funnel cloud reported at the same time 10 miles north of Denver possibly touched ground. Later…funnel clouds were reported 12 miles south-southeast of Stapleton International Airport…10 miles southwest…and 5 miles north. A tornado was sighted 3 1/2 miles east of Stapleton International Airport by weather bureau personnel for a duration of 5 minutes. Heavy rain and some hail fell over much of the area.

In 1974…the start of the shortest seasonal snow free period on record…94 days…occurred with the last snow of the season…a trace…on the 8th. The first snow of the next season occurred on September 11th when a trace of snow fell at Stapleton International Airport. A funnel cloud was observed just east of Aurora and a small funnel was sighted just northeast of Stapleton International Airport.

In 1985…a thunderstorm wind gust to 62 mph was reported at Golden Gate Canyon in the foothills west of Denver.

In 1986…a thunderstorm…which dumped heavy rain and caused some street flooding across north metro Denver…produced a small tornado 5 miles east of Brighton. No damage was reported.

In 1987…strong thunderstorm wind gusts in Conifer destroyed a porch on a house; the wind gust apparently picked up the porch and dropped it on a man…killing him. The wind also damaged the roof of the house and a nearby barn. The same thunderstorm spawned a tornado…which touched down briefly just south of Lakewood. No damage was reported. Up to 3 inches of rain fell in a short time 8 miles southwest of Littleton. A few businesses in Englewood suffered minor water damage. A tornado was sighted between Watkins and Bennett. It was on the ground for 15 minutes. A weak tornado also touched down 4 miles southwest of Castle Rock. The twister tossed an aluminum shed into the air and carried it about 100 feet. A funnel cloud was sighted 15 miles east-northeast of Stapleton International Airport.

In 1988…golf ball size hail fell in Conifer along with 1.30 inches of rain. Three miles north of Louisville…1.10 inches of rain fell in 20 minutes. Ping pong ball size hail was measured in Arvada.

In 1990…3/4 inch hail fell in Castle Rock.

In 1991…hail two inches in diameter fell near Evergreen. Hail to 1 inch diameter fell in Lakewood where a funnel cloud was also sighted. One inch diameter hail was also reported in Aurora.

In 2002…high temperatures…low relative humidities…and strong gusty winds allowed the Hayman wildfire…located in the foothills to the southwest of Denver…to become the largest wildfire in the state’s history. Although the fire was initially started by a U.S. Forest Service employee…the ongoing drought and dry conditions allowed the fire to spread rapidly out of control. The wildfire consumed nearly 138 thousand acres of forest land and 133 homes before it could be contained and finally extinguished on June 30th. About 1800 households had to be evacuated during the blaze. Southwest winds aloft swept the smoke plume directly over metro Denver…creating poor air quality and blocking the sun. Much of metro Denver choked on smoke with the southern suburbs receiving the most. Smoke and ash restricted surface visibilities to a mile or less at times in the Denver and Castle Rock areas and to 2 miles at Denver International Airport.

In 2003…thunderstorm winds gusted to 51 mph at Denver International Airport. The storm produced only a trace of rain.

In 2004…severe thunderstorms produced large hail across portions of metro Denver for the second day in a row. The most extensive damage occurred across southern sections of metro Denver in Aurora…Lakewood…Littleton…and south Denver. The combined damage to homes and vehicles…not including commercial buildings…was estimated at 146.5 million dollars…making the event the 4th costliest insurance disaster in the state’s history. Hail as large as 2 1/4 inches in diameter fell near southern Aurora with hail to 1 3/4 inches in the city of Denver and in Lakewood. Hail to 1 1/2 inches fell near Morrison with 1 inch hail measured in Thornton…near Buckley Air Force Base…and near Roggen. Hail to 3/4 inch diameter fell in Littleton and near Conifer. A small tornado touched down near Bennett…but did no damage.

Continue reading June 8 to June 14: This Week in Denver Weather History →

Weather History

June 1 to June 7: This Week in Denver Weather History

June 1, 2025 Thornton Weather Leave a comment

This Week in Denver Weather History

Severe weather is usually the hallmark of mid to late spring weather and our look back at this week features the types of events that make this ring true. Numerous cases of flooding rains, damaging hail and tornadoes are seen. Most notably is the infamous June 3, 1981 tornado in Thornton.

From the National Weather Service:

29-1

In 1894…heavy rain combined with snowmelt runoff caused widespread flooding over the South Platte River basin. Rainfall was heaviest in the foothills where 5 to 8 inches were measured over the 4 days. Heavy rainfall west of Boulder flooded mining towns and damaged mining properties. In the canyons above Boulder…railroads and roads were washed out along with many bridges. The floodwaters spread into central Boulder and covered a wide area from University Hill north to near Mapleton Hill to a maximum depth of 8 feet. Many houses were swept away…and every bridge in Boulder was destroyed. A few people…trapped in their homes by the floodwaters… Had to be rescued. However…the gradual rise of the flood waters resulted in only one death. Boulder Creek spread to a width of nearly one mile in the pasture land to the east of Boulder. Extensive flooding on Left Hand Creek north of Boulder washed away railroad and wagon bridges. The heavy cloudbursts caused flooding on bear creek…which washed away bridges…railroad tracks…and structures and destroyed the canyon roadway. Morrison sustained the heaviest flood damage on Bear Creek. In Denver…rainfall totaled only 1.50 inches on the 30th and 31st…but the heavy rainfall on upstream tributaries of the South Platte River caused the river to rise as much as 10 feet above the low water mark in the city…which caused some flooding of pasture land downstream to a depth of 6 feet near Brighton.

In 1875…a windstorm during the late afternoon and early evening produced sustained winds to 50 mph.

In 1898…south winds were sustained to 41 mph with gusts to 46 mph.

In 1917…a trace of unmelted snow fell in downtown Denver. Precipitation for the day totaled 0.08 inch…half of which was estimated to be from melted snow.

In 1919…snowfall of 0.4 inch was measured in downtown Denver. This was the greatest calendar day and 24-hour snowfall ever recorded during the month of June. Precipitation (rain and melted snow) totaled 0.15 inch. Two temperature records were set. The low temperature of 32 degrees was a record minimum for the date. The high temperature of only 40 degrees was a record low maximum for the date and the month. North winds were sustained to 36 mph with gusts to 40 mph.

In 1951…a trace of snow fell at Stapleton Airport.

In 1961…hail as large as 1 1/2 inches in diameter fell in west Denver with hail to 1 1/4 inches reported in derby.

In 1965…a man struck by lightning in southeast Denver died shortly after being admitted to a hospital. Lightning damaged power lines in east and southeast Denver.

In 1980…strong thunderstorm winds blew in the windows of a mobile home in Northglenn.

In 1990…a thunderstorm produced wind gusts to 63 mph in Boulder. A small tornado touched down in a farmer’s field between the towns of Louisville and Lafayette. Another tornado was spotted in an open field 3 miles west of Brighton. A funnel cloud was sighted near Hudson. A microburst wind gust to 55 mph was recorded at Stapleton International Airport. No damage was reported from any of these events.

In 1991…severe thunderstorms producing large hail…damaging winds…funnel clouds…and heavy rain were widespread across metro Denver. Funnel clouds were reported in Lakewood… Boulder…Arvada…and just east of the rocky mountain arsenal. Hail up to golf ball size fell in Lakewood…just west of Sedalia…in Littleton…Arvada…Englewood…and the city of Denver. A mobile home park in Jefferson County reported hail to 3 feet deep. Up to 1.00 inch of rain fell in 45 minutes near Boulder…causing Boulder creek to flow out of its banks. Rock and mud slides forced the closure of many roads in Boulder County. Later in the afternoon thunderstorms produced rainfall amounts of 2 to 3 inches over a couple of hours. Clear creek in Golden spilled over onto U.S. Highway 6. Heavy rains washed away part of a bridge near Erie. Water was up to 18 inches deep in Westminster. Wind gusts to 58 mph were reported at Stapleton International Airport where 1/4 inch hail fell… And heavy thunderstorm rainfall totaled 0.82 inches…briefly reducing the visibility to 1 1/4 miles. Estimates of total damage from these storms would exceed 7 million dollars.

In 1994…hail up to 1 inch in diameter fell over south Denver and Littleton.

In 1997…two short lived-tornadoes formed near Bennett…but did no reported damage.

In 2002…strong winds from the outflow of dissipating showers developed to the east of Denver. Near Strasburg…a spotter recorded a wind gust to 58 mph.

In 2019…severe thunderstorms produced large hail from 1 to 1 3/4 inch hail east of Centennial and over southeast Aurora.

1-2

In 2002…unusually very warm weather for so early in June resulted in two temperature records. Maximum temperatures of 96 degrees on the 1st and 93 degrees on the 2nd were record highs for each date…respectively.

1-4

In 1977…unusually warm weather for this early in June resulted in 3 maximum temperature records being equaled at the time: 88 degrees on the 1st…90 degrees on the 2nd… And 93 degrees on the 4th. Maximum of 91 degrees on the 3rd was not a record.

1-30

In 1914…flooding occurred on Boulder creek when heavy rains added to heavy snowmelt runoff. Flooding damaged the water supply system from the mountains into Boulder and destroyed roads and bridges in the canyons above Boulder. The flooding in central Boulder was described as the worst since the tragic flood of May 29th through June 3rd in 1894. However…there was no reported loss of life. The flood waters also inundated pasture land to the east of the town.

In 1951…the lowest recorded temperature in June…30 degrees… Occurred. The unusually cold weather was accompanied by 0.3 inch of snowfall. Precipitation…both rain and melted snow…totaled 0.30 inch.

In 1966…microburst winds gusted to 51 mph at Stapleton International Airport.

In 1981…a severe thunderstorm roared through metro Denver… Dumping 2.00 inches of rain in as little as 20 minutes and bombing many areas with hail to 1 3/4 inches in diameter. The heavy rain caused local flooding with up to 3 feet of water in some streets in northwest metro Denver. Part of a street was washed out in Thornton. Lightning strikes started a fire and caused a power outage just north of Denver. Lightning also struck a barn which burned to the ground in Brighton. Numerous cars sustained minor hail damage. A tornado was spotted 4 miles northeast of the rocky mountain arsenal…but caused no damage.

In 1982…severe thunderstorms produced large hail across metro Denver. Hail to 3/4 inch in diameter was reported in Louisville and northeast Denver. Golf ball size hail fell near Strasburg where two tornadoes were also sighted.

In 1983…a tornado touched down 5 miles south of Bennett. It destroyed an outbuilding and did extensive damage to greyhound dog shelters. Golf ball size hail fell near the tornado…destroying some hay.

In 1985…3/4 inch hail fell in southwest metro Denver.

In 1989…large hail fell over eastern and central Denver. A few stones were as large as baseballs…and many ranged from 3/4 inch to golf ball size. The hail piled up 2 to 4 inches deep in some areas. Hail to 3/4 inch fell at Buckley Field in Aurora…and 7/8 inch hail fell just east of Aurora. A home in Louisville was struck by lightning and was 30 percent destroyed by the ensuing fire.

In 1991…strong thunderstorm winds in Arapahoe County…14 miles southeast of Stapleton International Airport…damaged the roof of a home and a radio antenna. A funnel cloud… 4 miles northeast of Stapleton International Airport…was sighted for 11 minutes by national weather service observers.

In 1993…a tornado touched down briefly in south Denver… Destroying the 4-inch thick concrete roof of a building and causing about 20 thousand dollars in damage. The twister also picked up a trash dumpster and dropped it onto a car 30 feet away…causing an estimated 3 thousand dollars in damage. Hail up to an inch in diameter fell in Aurora… Conifer…and Bennett. Two funnel clouds were spotted near Deckers. A funnel cloud was sighted for 19 minutes by national weather service observers to the southwest of Stapleton International Airport.

In 1994…lightning struck two homes in Denver…starting fires which caused considerable damage to both. Hail to 3/4 inch in diameter fell in Golden.

In 1995…lightning struck a house in Nederland…causing a fire that was doused by subsequent rainfall. A portion of the roof and wall was damaged. The storm also left most of Nederland without power for two hours. Lightning also struck a high chimney of an elementary school in west Denver. The jolt sprayed bricks around the school yard and parking lot. Twenty students and teachers were in the school building at the time…but all escaped without injury. A funnel cloud was sighted over Fort Lupton…and 3/4 inch hail fell in Lafayette.

In 2003…severe thunderstorms produced strong winds and large hail. Hail as large as 1 1/2 inches in diameter fell near Parker. Estimated wind gusts to 70 mph occurred near Parker and near Denver International Airport where thunderstorm wind gusts to 52 mph were recorded. Wind gusts to 60 mph were estimated near Bennett.

In 2005…a severe thunderstorm produced hail as large as 1 inch in diameter in the city of Denver. A tornado was sighted near Bennett along with 3/4 inch hail.

In 2008…severe thunderstorms produced large hail over western Arapahoe…northern Denver and southern weld counties. Hail…2 inches in diameter…was observed near Brighton; with hail to 1 1/2 inches in diameter…5 miles east of prospect. Hail to one inch in diameter was observed near Buckley Field…Frederick and Denver.

In 2012…severe thunderstorm produced damaging thunderstorm winds. Peak wind gusts included: 82 mph near Strasburg… 61 mph at Buckley Field…60 mph near byers and southwest Denver…58 mph near Watkins and 52 mph at Denver International Airport. The microburst winds caused extensive tree and roof damage. In addition…hail up to 1 inch in diameter was reported 3 miles east-southeast of Parker.

In 2019…lightning struck a home in Broomfield. Minor damage to the roof was observed.

2-4

In 1989…heavy rain drenched metro Denver with the greatest amounts recorded on the 3rd. Total rainfall ranged from 1 1/2 to 3 inches. Roads were washed out in Boulder County… And flooded basements caused water damage to houses in the Gunbarrel section of Boulder. In suburban Denver…heavy rain caused minor flooding along Lena Gulch in Jefferson County where two mobile home parks were evacuated. Rainfall totaled 1.66 inches at Stapleton International Airport.

Continue reading June 1 to June 7: This Week in Denver Weather History →

Weather History

May 25 to May 31: This Week in Denver Weather History

May 25, 2025 Thornton Weather Leave a comment

This Week in Denver Weather History

Spring severe weather takes a front seat in our look back at this week in Denver weather. There are flooding rains, tornadoes and many occurrences of people being hurt or killed by lightning.

From the National Weather Service:

18-26

In 2023…smoke and haze from massive wildfires in Canada significantly impacted air quality and visibility across Denver and the rest of northeast Colorado.

20-27

In 2002…lightning sparked a wildfire near Deckers. Extremely dry conditions and very strong winds the following day allowed the fire…known as the Schoonover…to consume 3850 acres before it could be contained. Thirteen structures were destroyed…including 4 homes…resulting in 2.2 million dollars in damage.

24-26

In 1996…a late spring snowstorm dumped 4 to 10 inches of snow over the Front Range foothills. Conifer picked up 10 inches of new snow; Aspen Springs…9 inches; and central city…8 inches. The sticky…heavy snow clung to power lines and pulled tree branches down…causing power outages to about 1200 homes in the Conifer area. It took up to 6 hours to restore power to some residences. Lightning struck a telephone data cabinet in Conifer on the 25th…which knocked out phone service to about 1500 customers. Widespread rain fell across metro Denver… Where rainfall totaled 2.07 inches at the site of the former Stapleton International Airport and 1.66 inches at Denver International Airport where north winds gusted to 24 mph on the 26th.

In 2010…high winds preceding a cold front…swept across the Front Range foothills and urban corridor. In Aurora… The wind damaged the roof of Rangeview High School. In Conifer and Denver…the wind downed trees and power lines and caused several brief outages. The downed power lines also caused several cars to catch fire in the vicinity of 1590 Cook St. in Denver. Peak wind gusts included: 82 mph at Highlands Ranch…67 mph…4 miles east of Franktown and Longmont; 65 mph in Boulder…64 mph in Centennial and Denver International Airport…62 mph near Parker and 60 mph in Arvada.

In 1877…lightning killed one person in west Denver and struck several houses. The bolt struck the house of the “home laundry” stunning the occupants and killing a lady who was holding one of her grandchildren in her arms. The child escaped unhurt. The lightning also struck the top of a tree in front of the house and partially peeled the bark off the tree. Lightning struck a church in the Evans addition and another tree in east Denver. Lightning struck the switch room at the telegraph office where the operator saw small balls of lightning pass across the room to the stove. The thunderstorm pelted the city with only pea size hail. Precipitation from the storm totaled 0.40 inch in downtown Denver.

In 1880…light rain all afternoon totaled only 0.24 inch in the city…but was valuable to stockmen and farmers due to the very dry…parched weather conditions on the plains.

In 1965…a tornado was sighted by a pilot 30 miles south southeast of Denver. No damage was reported. Another pilot reported 3/4 inch hail 30 miles east of Denver. The state patrol reported that a man was killed when a fierce gust of wind swept him from the back of a pick-up truck in northwest Douglas County. The man was holding a mattress in the bed of the truck.

In 1974…a microburst wind gust to 53 mph was recorded at Stapleton International Airport. A pilot reported a tornado 20 miles east of Denver.

In 1976…lightning struck a home in Boulder…shattering 2 large trees and damaging a television set.

In 1997…hail as large as 1 3/4 inches in diameter fell near Watkins. Hail to 3/4 inch in diameter fell in Broomfield and near Lochbuie.

In 2000…3/4 inch diameter hail fell at Cheery Creek Reservoir in Aurora. Thunderstorm winds gusted to 51 mph at Denver International Airport where small hail fell.

In 2006…a severe thunderstorm produced an estimated wind gust to 70 mph in Hudson. The strong winds damaged the roof of a home. A thunderstorm produced southwest wind gusts to 54 mph at Denver International Airport.

25-26

In 1950…a major storm dumped 10.0 inches of snowfall downtown and 10.7 inches at Stapleton Airport where northwest winds gusted to 30 mph on the 25th. The storm caused extensive damage to utility wires and trees which were in full leaf. A daily record minimum temperature of 31 degrees occurred on the 25th. This was the coldest temperature on this date in 79 years and for so late in the season.

In 1989…a late season snow storm dropped snow as low as 6 thousand feet along the Front Range. Most places in the foothills had 2 to 5 inches of snow. Overnight rainfall totaled 0.33 inch at Stapleton International Airport where north winds gusted to 37 mph on the 25th.

In 1994…lightning struck a television transmitter on Lookout Mountain near Golden and burned out a switcher…which disrupted cable service for 2 hours.

In 1897…apparent post-frontal north winds were sustained to 42 mph with gusts as high as 48 mph.

In 1942…the all-time highest recorded temperature in May…95 degrees…occurred.

In 1978…two children were struck and killed by lightning on a junior high school playground in Parker.

In 1987…1 inch diameter hail fell near Boulder and Bennett. The hail was fairly soft and caused no damage.

In 1993…dry thunderstorms produced wind gusts to 81 mph at Jefferson County Airport near Broomfield. Several trees were blown down by the strong winds. Microburst winds gusted to 51 mph at Stapleton International Airport.

In 1995…a woman was injured in Littleton when the car she had just entered was struck by lightning. All of the windows in the car were blown out by the strike. A funnel cloud was sighted near Littleton.

In 2000…a strong microburst wind gust to 92 mph flipped a small airplane on its back and blew a dc-3 loose from its moorings…which allowed it to roll onto a grassy field at Front Range airport near Watkins.

In 2010…severe thunderstorms pounded parts of the urban corridor with very large hail…heavy rain…damaging winds and a tornado. The hail…ranging in size from 1 inch to 2 3/4 inches in diameter…struck Brighton…Commerce City and northeast Denver the hardest. The storms continued to spread destruction to the north and east…impacting byers…Hudson…Deer Trail and Prospect Valley. The combination of hail and wind stripped the bark and branches from trees. Numerous accidents were reported as the hail accumulated up to a foot deep. Snowplows were called out to clear the roadways. Flash flooding occurred along State Highway 52 between Hudson and Keenesburg…and forcing the closure of the highway. Widespread crop damage was also reported as the area was inundated with up to 18 inches of water. Extensive damage to homes…businesses and automobiles was reported with the damage estimated to be around 70 million dollars. A tornado touched down near Denver International Airport…but did no damage. Lightning struck a child in Commerce City while she was watching television. She suffered minor injuries to her leg. At the Rocky Mountain Arsenal Wildlife Refuge…a lightning strike killed a bison. At Denver International Airport…only 0.01 inch of rainfall was observed…along with a peak wind gust to 48 mph from the southeast.

In 2016…severe thunderstorms produced hail up to one inch in diameter near Castle Rock…The Pinery and Watkins.

In 2019…severe thunderstorms broke out across parts of Adams…Arapahoe…Denver…and southern Weld counties during the late afternoon and early evening. The hail ranged from 1 to 1 1/2 inch in diameter. At Denver International Airport…up to 3 inches of hail accumulated on runway surfaces. Consequently…dozens of flights were either delayed or cancelled so runways could be cleared and aircraft inspected for hail damage. A peak wind gust to 44 mph was observed from the west at Denver International Airport…with 0.65 inch of rainfall.

Continue reading May 25 to May 31: This Week in Denver Weather History →

Weather History

May 18 to May 24: This Week in Denver Weather History

May 18, 2025 Thornton Weather Leave a comment

This Week in Denver Weather History

The further we get into May, the chances for severe weather increase. This is readily seen in our look back at this week in Denver weather history. The majority of the events involve springtime severe weather like heavy rains that result in flooding, large damaging hail, dangerous lightning and an increase in tornadoes.

From the National Weather Service:

14-18

In 1996…a period of unusually warm weather resulted in 4 record maximum temperatures in 5 days. The record high temperatures were 87 degrees on the 14th…89 degrees on the 15th…and 93 degrees on both the 16th and 18th. The temperature climbed to only 81 degrees on the 17th which was not a record.

17-19

In 2017…a strong spring storm dropped across the Great Basin… and then moved eastward across Colorado. Isolated but strong thunderstorms preceded the system on the 17th with hail up to nickel size near Boulder Airport and Brighton. Significant snow fell across the Front Range mountains and foothills over the next couple of days. Along the Interstate 25 Corridor… rain turned to snow on the morning of the 18th…heaviest from around Broomfield northward. The heavy wet snow snapped the limbs of fully leaved trees and caused scattered power outages. A barns collapsed in northeast Loveland. Fifty-five head of cattle were inside the collapsed barn; three were injured and later euthanized. Numerous branches and trees snapped in the foothills. Elsewhere…several scattered smaller power outages were reported. Three to nearly five inches of liquid precipitation occurred…as rain or a mix of rain and snow…fell around Greeley. Storm totals in the Front Range mountains and foothills included: 42.0 inches near Allenspark…41.5 inches near Ward…36 inches at Estes Park… 32 inches near Pinecliffe…30.5 inches northwest of Golden… 30 inches near Nederland…26 inches near Breckenridge…25 inches near Aspen Springs and Bear Lake State Park…14 inches at Aspen Springs…with 9.5 inches near Evergreen. On the west side of the Interstate 25 Corridor…storm totals included: 10 inches near Superior and Louisville…6 to 8 inches in and around Fort Collins…6 inches in Lafayette… 5 inches in Broomfield and Loveland…and 4 inches near Niwot.

In 1864…heavy rains combined with melting snow to cause much flooding on north clear creek in Blackhawk. Many bridges on the road to Denver were washed away by the high water on clear creek.

In 1893…northwest winds were sustained to 56 mph with an extreme velocity to 60 mph.

In 1960…large hail to 1 inch in diameter damaged roofs and cars in metro Denver. Heavy snow and rain in the foothills caused rock and landslides…which blocked some highways. There was widespread minor damage from lightning. Hail as large as 1 1/8 inch in diameter was measured at Stapleton Airport where winds gusted to 44 mph.

In 1975…a tornado touched down briefly just south of Buckley Field in Aurora. A few minutes later the same tornado touched down in open country 8 miles northeast of Stapleton International Airport. No damage was reported.

In 1985…3/4 inch hail fell just southeast of Aurora.

In 1988…lightning started a fire at a home in the foothills west of Boulder…causing 50 thousand dollars in damage.

In 1995…strong thunderstorms rumbled across metro Denver dropping mainly pea to marble size hail. However…hail stones as large as 1 1/4 inches in diameter fell in Wheat Ridge and downtown Denver. Hail piled up to 2 inches deep in Wheat Ridge and northwest Denver.

In 1996…the Buffalo Creek Wildfire started and spread rapidly on strong southwest winds at 20 to 30 mph. Dry weather conditions contributed to the spread of the fire… Which burned nearly 12 thousand acres and destroyed 12 structures including some houses.

In 2001…a 19-year-old man was struck and killed by lightning as he was walking along the shoulder of U.S. Highway 36 in Westminster.

In 2003…hail to 3/4 inch in diameter was measured at Denver International Airport.

In 2010…a small tornado touched down near Firestone but did no damage.

18-19

In 2011…a severe thunderstorm in central Adams County produced large hail and heavy rainfall on the 18th. Large hail from 1 inch to 1 3/4 inches in diameter…was reported in Commerce City…2 miles south-southeast of Federal Heights…Northglenn…and 2 miles south of Thornton. In Commerce City…the storm uprooted trees and knocked out power lines. A carport was lifted off the ground and struck the power lines overhead. Heavy rain…from 1.0 to 1.5 inches fell in less than 2 hours in Commerce City and near Brighton. The combination of hail and strong winds broke windows in Northglenn. In the foothills…moderate to heavy snow showers developed overnight. Storm totals included: 10.5 inches at gold hill…9.5 inches…3 miles west of Jamestown; 9 inches at Lake Eldora; with 6 inches… 11 miles southwest of Gilpin and 4 miles east-northeast of Nederland. At Denver International Airport…total rainfall over the 2-day period totaled 1.71 inches. In addition…a peak wind gust to 37 mph was recorded on the 18th.

18-20

In 1915…3.9 inches of snow fell in the city. The estimated amount of snow that melted as it fell was 6.2 inches which would have totaled an estimated 10.1 inches of snowfall. Precipitation totaled 1.03 inches. North winds were sustained to 32 mph on the 18th. Low temperatures dipped to 25 degrees on both the 18th and 20th…establishing record minimums for both dates.

In 1988…prolonged heavy rainfall drenched metro Denver. The event began when heavy thunderstorms on the 18th caused some street flooding and power outages…followed by steady rain on the 19th and 20th. Rain amounts across metro Denver totaled 3 to 4 inches. Rainfall totaled 3.71 inches at Stapleton International Airport where north winds gusted to 39 mph on the 20th. Four to eight inches of snow fell in the foothills above 7 thousand feet.

18-26

In 2023…smoke and haze from massive wildfires in Canada significantly impacted air quality and visibility across Denver and the rest of northeast Colorado.

In 1927…southeast winds were sustained to 40 mph with gusts to 44 mph.

In 1956…a thunderstorm wind gust to 54 mph was recorded at Stapleton International Airport.

In 1969…hail stones to 1 inch in diameter were measured in Arvada and Aurora. Some minor damage was reported. Pea to marble size hail fell in Westminster.

In 1972…a tornado was reported by aircraft about 5 to 10 miles east of Parker.

In 1988…lightning started a fire at a house in the Denver suburb of Greenwood Village…causing 2 thousand dollars in damage.

In 1991…strong thunderstorms over east metro Denver produced wind gusts of 56 to 60 mph. The strong winds downed power lines…trees…and fences at some locations in Aurora. Thunderstorm outflow winds gusted to 60 mph at Stapleton International Airport.

In 1994…severe thunderstorms rumbled across metro Denver. The storms produced wind gusts averaging 65 mph and hail up to dime size. Wind gusts to 77 mph were recorded in Brighton. Numerous trees and power poles were downed by the winds. One power pole fell onto spectators at a high school graduation ceremony in Commerce City…injuring 6 people. In Fort Lupton…trees fell onto 2 parked cars… Knocking out the windshields. Hail to 3/4 inch in diameter was reported in Littleton. A thunderstorm wind gust to 52 mph was recorded at Stapleton International Airport.

In 1995…a slow moving tornado…which was mainly discernible by its dust and debris cloud…was spotted 2 miles northeast of Denver International Airport or about 10 miles northwest of Bennett. No damage was reported.

In 2007…lightning struck a 33-ft statue of Jesus at Mother Cabrini Shrine…in the foothills west of Golden. The blast broke off one of the statue’s arms and a hand…and also damaged a foot. It cost an estimated $200000 to repair.

In 2009…lightning struck the roof of a residence in Highlands Ranch. The home was not a total loss…but the fire caused extensive damage.

In 2010…a thunderstorm produced hail up to 7/8 inch in diameter in Thornton.

Continue reading May 18 to May 24: This Week in Denver Weather History →

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