Tag Archives: July Weather

July 14 to July 20: This Week in Denver Weather History

This Week In Denver Weather History
July 14 to July 20: This Week in Denver Weather History

Monsoonal rain, dangerous lightning and large hail are all par for the course as we see in our look back at this week in Denver weather history. But, what about snow? Yes, you read that right. Denver did actually record snowfall on July 17, 1872 but because it occurred before official snowfall measurements began in the young Mile High City, it doesn’t count. See below for complete details.

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.

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.

14

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 Cherry 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.

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.

15

In 1879…a terrific hail storm occurred in the vicinity of Buffalo Station on the South Park Railroad in the South Platte River Canyon about 39 miles south of Denver. Stones as large as hen’s eggs fell thick and fast and broke nearly every pane of glass in the windows of the building. A “waterspout” or cloudburst caused much loss of property from flash flooding on a nearby gulch. The torrent of water caused a deafening roar as it uprooted trees and carried huge Boulders and other debris. It struck the house and sawmill simultaneously and carried them away like straws…leaving little behind. The water continued to rush down the gulch for several hours. Serious damage was done to the south park railroad. The track and roadbed were destroyed for several miles. At about the same time…heavy rains in the vicinity of the headwaters of Cherry Creek produced a rapid rise in the creek…which drowned a few head of cattle and washed away two footbridges and some fences. Only 0.10 inch of rainfall was recorded in Denver.

In 1896…a thunderstorm produced sustained southwest winds to 40 mph with gusts to 46 mph.

In 1902…the temperature reached a high of 100 degrees in downtown Denver…which was a record maximum for the date.

In 1929…a thunderstorm did considerable damage to property in the eastern portion of the city. Heavy hail ranging in size from 1/4 to 3/4 inch in diameter…severe lightning… And high winds accompanied the heavy rain. Basements were flooded…and streets were impassable in places for several hours due to the heavy rainfall. Lightning damaged several telephone poles. Hail did extensive damage to gardens and flowers. The hail was up to a foot deep in places. There was no estimate of damage from the storm. A thunderstorm produced only a trace of rain and east winds to 24 mph in downtown Denver.

In 1959…thunderstorm rain totaled 0.41 inch in 8 minutes and winds gusted to an estimated 50 mph near downtown Aurora where half inch diameter hail was also reported. After the storm moved to the east…complete double rainbows were observed from the weather bureau office at Stapleton Airport.

In 1962…hail pelted the area in Adams County around Henderson and Brighton…causing extensive damage to corn…grain… Beets…and row crops. Crop damage was estimated at 250 thousand dollars.

In 1963…a man received severe burns when struck by lightning while painting a building in south Denver.

In 1965…a state patrolman sighted a tornado near Bennett. It touched down over open ground…but caused no damage.

In 1967…heavy rains flooded streets and underpasses in south Denver. Heavy rain and minor wind damage were reported in Wheat Ridge…Aurora…Englewood…and Littleton. Basements were flooded and power disrupted. The clouds and rain resulted in a high temperature of only 72 degrees…which was a record low maximum for the date.

In 1974…a severe lightning storm damaged several homes and caused a number of power outages in both Denver and western Arapahoe counties.

In 1975…lightning killed a girl west of Boulder.

In 1982…winds gusted to 60 mph at Stapleton International Airport…and strong winds blew down walls at a construction site in Aurora where a nearby tree was uprooted.

In 1985…0.79 inch of rain fell in 30 minutes at Castle Rock. Much of the town lost power when lightning struck the town’s transformer.

In 1992…a man was struck by lightning while horseback riding near Castle Rock. Two people were struck by lightning near Highlands Ranch in south metro Denver. A man was struck by lightning while riding in the back of a pick-up truck in Franktown. All received minor injuries. Strong thunderstorms moved through east metro Denver…producing large hail and flash flooding. Hail up to 1 1/4 inches in diameter fell near Buckley Air National Guard base. Rainfall of 1 to 3 inches fell in Aurora in less than an hour…leaving water up to 18 inches deep in some areas. Thunderstorm rainfall was measured at 0.97 inch at Stapleton International Airport…where 3/8th inch diameter hail fell and south winds gusted to 44 mph.

In 1993…dime size hail fell in Golden. National weather service observers at Stapleton International Airport sighted a small rope-like funnel overhead for about 3 minutes before it dissipated.

In 1994…a small…short-lived tornado caused damage to a house under construction in Parker.

In 1995…thunderstorm winds of unknown strength downed trees and branches…damaging a porch and nearby cars in Denver.

In 1998…hail to 7/8 inch in diameter fell near Keenesburg.

In 2000…this date marked the end of a near record hot streak for metro Denver. The high temperature at Denver International Airport equaled or exceeded the 90-degree mark for 17 consecutive days…from June 29th. This was one day short of equaling the all-time record. The record of 18 consecutive days was set in two different years…July 1st-18th…1874 and July 6th-23rd…1901.

In 2005…severe thunderstorms produced large hail over southeast metro Denver. Hail as large as 1.75 inches in diameter fell in southwest Aurora along with 7/8 inch hail in Centennial. Hail to 3/4 inch in diameter was measured near Centennial Airport and near Watkins.

Continue reading July 14 to July 20: This Week in Denver Weather History

July 7 to July 13: This Week in Denver Weather History

This Week In Denver Weather History
July 7 to July 13: This Week in Denver Weather History

Severe weather becomes a bit less common as we get further into summer but the threat is never gone as we see in our look back at this week in Denver weather history. Many notable events related to severe thunderstorms have occurred including flooding rain, tornadoes and damaging hail.

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

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.

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.

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

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.

Continue reading July 7 to July 13: This Week in Denver Weather History

June 30 to July 6: This Week in Denver Weather History

This Week In Denver Weather History
June 30 to July 6: This Week in Denver Weather History

Dangerous lightning, damaging hail and even tornadoes make the highlights of our look back at this week in Denver weather history.

From the National Weather Service:

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

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.

30

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.

Continue reading June 30 to July 6: This Week in Denver Weather History

NOAA: July 2012 goes into record books as hottest month ever for United States

Sweltering, unseasonably warm temperatures gripped much of the contiguous United States last month breaking many records. In the final analysis of the month, NOAA announced that July was the hottest month ever recorded in the U.S.  How hot was it?  Read the rest of this story on Examiner.com

Much of the Lower 48 states saw above average temperatures during July 2012.  Click the image to view the story and slideshow.
Much of the Lower 48 states saw above average temperatures during July 2012. Click the image to view the story and slideshow. (NOAA)

July 2012 Thornton weather recap: Month goes into books as hottest recorded

Thornton's July 2012 weather recap
Thornton recorded its hottest month of the past six years during July 2012.

For the second month in a row, Thornton saw extraordinarily warm temperatures in July.  The month not only was the warmest July ever recorded by ThorntonWeather.com, it was the warmest month recorded since we began operation.

The average temperature for July 2012 was an astonishing 75.5 degrees.  This was 1.8 degrees above Thornton’s average for July over the past six years, a significant increase.

Temperatures ranged from a high of 98.7 degrees on July 1 down to a low of 56.6 degrees on July 11.

In all we recorded 23 days with high temperatures at or above 90 degrees.  We did however manage to escape the month without breaking the century mark.

In terms of precipitation Thornton didn’t fare too poorly.  We recorded 1.92 inches of precipitation in our rain bucket.  This was only 0.03” below the six year average of 1.95 inches.

For comparison, Denver saw an official average monthly temperature of 78.9 degrees as measured at Denver International Airport.  Further, they only recorded 0.48 inch of precipitation.  For more details on Denver’s July 2012 weather, please visit this story on Examiner.com.

More on ThorntonWeather.com:

July 2012 Graphs

Thornton's July 2012 Temperatures

Thornton's July 2012 precipitation

July 29 to August 4 – This Week in Denver Weather History

This Week In Denver Weather History
July 29 to August 4 - This Week in Denver Weather History

The effects of our annual monsoon season are portrayed in detail in our look back at this week in Denver weather history. Numerous cases of flooding resulting from heavy rainfall are seen as are other severe weather events including hail and even tornadoes.

From the National Weather Service:

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.
27-31 in 1956…96 percent of the total precipitation for the month of July occurred over the last five days of the month. Heavy thunderstorms produced 4.00 inches of rainfall at Stapleton Airport. This amount of precipitation in 5 days or less had been exceeded only 3 times in previous record. The last time had been in December of 1913 as snow. Considerable property damage occurred across metro Denver from flooding.

28-30

In 1889…dense smoke from forest fires in the mountains obscured the sun over the city for three days.

In 1971…a vigorous cold front late on the 28th produced northeast wind gusts to 39 mph and record breaking cold temperatures on the 29th and 30th. The temperature dipped to 47 degrees on the 29th and 43 degrees on the 30th… Setting record minimums for the dates. Upslope cloudiness along with rain and fog early on the 29th helped set a record low maximum temperature of 58 degrees for the date.

29

In 1878…a total eclipse of the sun was observed at 2:20 pm. From before to during the eclipse…the temperature in the sun fell from 114 degrees to 82 degrees…while the shade temperature fell from 89 degrees to 83 degrees.

In 1880…heavy thunderstorm rain and hail flooded streets and ditches.

In 25 minutes…0.76 inch of rain fell on the city along with large hail to 3/4 inch in diameter. There were no strong winds with the storm.

In 1890…a thunderstorm produced sustained west winds to 48 mph with gusts to 60 mph…but only 0.01 inch of rain.

In 1956…heavy rain and hail fell over west and north Denver.

In 1964…hail to 3/4 inch in diameter fell at Lowry Airfield.

In 1978…a small tornado was sighted just east of Parker. No damage was reported.

In 1989…heavy rain drenched all areas of the Front Range… Both in the foothills and adjacent plains. Amounts of 1 to 3 inches were general over the area. Damage was confined to a few minor road washouts and some street…basement…and crop flooding. Thunderstorm rainfall totaled 1.44 inches at Stapleton International Airport where north winds gusted to 43 mph. Lightning struck a 250 thousand dollar home near Nederland and started a fire which destroyed all of it except two garages. Lightning started a fire in a home in Evergreen. It reached the house by hitting a tree…then traveling through a metal clothesline strung between the tree and the building.

In 1995…thunderstorm winds gusted to 59 mph in Brighton. Thunderstorm winds from the south-southeast gusted to 41 mph at Denver International Airport. High temperature of 99 degrees was a new record maximum for the date in Denver.

In 1997…heavy rain caused flooding in an apartment building in Westminster. Several residents had to be evacuated from their apartments. A woman in aspen park received minor injuries…when lightning passed through an office window and struck her. She suffered temporary blindness for about 15 minutes.

In 2003…hail as large as 1 inch in diameter pelted Conifer… Highlands Ranch…and Franktown.

Continue reading July 29 to August 4 – This Week in Denver Weather History

July 15 to July 21 – This Week in Denver Weather History

This Week In Denver Weather History
July 15 to July 21 - This Week in Denver Weather History

Denver’s weather is rarely boring and our look back at this week in Denver weather history shows that. There have certainly been many notable thunderstorms with hail and damaging wind. However the most interesting item is the first – and only – recorded instance of snow during the month of July in the Mile High City.

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.

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.

15

In 1879…a terrific hail storm occurred in the vicinity of Buffalo Station on the south park railroad in the South Platte River canyon about 39 miles south of Denver. Stones as large as hen’s eggs fell thick and fast and broke nearly every pane of glass in the windows of the building. A “waterspout” or cloudburst caused much loss of property from flash flooding on a nearby gulch. The torrent of water caused a deafening roar as it uprooted trees and carried huge Boulders and other debris. It struck the house and sawmill simultaneously and carried them away like straws…leaving little behind. The water continued to rush down the gulch for several hours. Serious damage was done to the south park railroad. The track and roadbed were destroyed for several miles. At about the same time…heavy rains in the vicinity of the headwaters of Cherry Creek produced a rapid rise in the creek…which drowned a few head of cattle and washed away two footbridges and some fences. Only 0.10 inch of rainfall was recorded in Denver.

In 1896…a thunderstorm produced sustained southwest winds to 40 mph with gusts to 46 mph.

In 1902…the temperature reached a high of 100 degrees in downtown Denver…which was a record maximum for the date.

In 1929…a thunderstorm did considerable damage to property in the eastern portion of the city. Heavy hail ranging in size from 1/4 to 3/4 inch in diameter…severe lightning… And high winds accompanied the heavy rain. Basements were flooded…and streets were impassable in places for several hours due to the heavy rainfall. Lightning damaged several telephone poles. Hail did extensive damage to gardens and flowers. The hail was up to a foot deep in places. There was no estimate of damage from the storm. A thunderstorm produced only a trace of rain and east winds to 24 mph in downtown Denver.

In 1959…thunderstorm rain totaled 0.41 inch in 8 minutes and winds gusted to an estimated 50 mph near downtown Aurora where half inch diameter hail was also reported. After the storm moved to the east…complete double rainbows were observed from the weather bureau office at Stapleton Airport.

In 1962…hail pelted the area in Adams County around Henderson and Brighton…causing extensive damage to corn…grain…beets…and row crops. Crop damage was estimated at 250 thousand dollars.

In 1963…a man received severe burns when struck by lightning while painting a building in south Denver.

In 1965…a state patrolman sighted a tornado near Bennett. It touched down over open ground…but caused no damage.

In 1967…heavy rains flooded streets and underpasses in south Denver. Heavy rain and minor wind damage were reported in wheat ridge…Aurora…Englewood…and Littleton. Basements were flooded and power disrupted. The clouds and rain resulted in a high temperature of only 72 degrees…which was a record low maximum for the date.

In 1974…a severe lightning storm damaged several homes and caused a number of power outages in both Denver and western Arapahoe counties.

In 1975…lightning killed a girl west of Boulder.

In 1982…winds gusted to 60 mph at Stapleton International Airport…and strong winds blew down walls at a construction site in Aurora where a nearby tree was uprooted.

In 1985…0.79 inch of rain fell in 30 minutes at Castle Rock. Much of the town lost power when lightning struck the town’s transformer.

In 1992…a man was struck by lightning while horseback riding near Castle Rock. Two people were struck by lightning near Highlands Ranch in south metro Denver. A man was struck by lightning while riding in the back of a pick-up truck in Franktown. All received minor injuries. Strong thunderstorms moved through east metro Denver…producing large hail and flash flooding. Hail up to 1 1/4 inches in diameter fell near Buckley Air National Guard base. Rainfall of 1 to 3 inches fell in Aurora in less than an hour…leaving water up to 18 inches deep in some areas. Thunderstorm rainfall was measured at 0.97 inch at Stapleton International Airport…where 3/8th inch diameter hail fell and south winds gusted to 44 mph.

Continue reading July 15 to July 21 – This Week in Denver Weather History

July 8 to July 14 – This Week in Denver Weather History

This Week In Denver Weather History
July 8 to July 14 - This Week in Denver Weather History

In looking back at this week in Denver weather history, one cannot be struck by the hail storms listed, if not for sheer number then by the damage they caused. The biggest of these storms occurred in 1990 and stands in the books as the most damaging hailstorm in United States history.

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.

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

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.

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.

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.

8

In 1905…a thunderstorm produced 0.82 inch of rainfall and northeast winds sustained to 48 mph.

In 1977…strong winds turned over 2 light aircraft at Arapahoe County Airport…now centennial airport.

In 1987…a weak tornado was observed near Bennett.

In 1988…three separate tornadoes were sighted near Bennett. No damage was reported. One inch diameter hail was also reported.

In 1991…lightning started three house fires in Castle Rock. Damage totaled 13 thousand dollars. No injuries were reported.

In 1993…a dry thunderstorm microburst wind gust to 55 mph briefly reduced the surface visibility to 3 miles at Stapleton International Airport.

In 1997…one construction worker was killed and two others injured when a strong thunderstorm wind gust caused the scaffolding they were standing on to collapse near Parker. A dry microburst produced a wind gust to 54 mph at Denver International Airport.

In 1998…heavy thunderstorm rain forced the closure of Hampden Avenue between I-25 and Havana Street in southeast Denver. The high water made 2 or 3 lanes of the street impassable.

In 2001…severe thunderstorms produced large hail…damaging winds…and heavy rain across south metro Denver. Two people received minor injuries when a severe thunderstorm wind gust to 58 mph blew over several tents at the Cherry Creek Arts Festival. The same storm caused the roof of a hardware store in Tamarac Square to collapse. One employee received minor injuries when she was struck in the head by falling debris. The combination of intense rain and wind downed trees and power lines. Electrical power outages affected 35 thousand homes and businesses. At least 50 trees in city parks across south Denver were damaged. Up to 4.50 inches of thunderstorm rain fell across portions of southeast metro Denver. The underpass at I-25 and Parker road was inundated with 5 feet of water. Several other streets and underpasses in Aurora were also closed due to high water. Heavy rain caused extensive damage to several exhibits at the Cherry Creek Arts Festival. Flash flooding occurred when heavy thunderstorm rainfall caused toll gate creek to jump its banks. Several underpasses across south Denver had to be closed due to high water. A man received minor injuries when lightning struck a nearby tree at the Wellshire Golf Course. Hail as large as 1 1/4 inches in diameter fell in Englewood with 1 inch hail in the city of Denver…and 3/4 inch hail in Littleton. Thunderstorm winds gusted to 63 mph at Denver International Airport and to 62 mph in Englewood.

In 2005…a tornado touched down briefly near Brighton…but caused no damage.

In 2011…severe thunderstorms produced hail…up to 1 inch in diameter…and wind gusts to 60 mph across parts of Adams…Broomfield and Denver counties. At Denver International Airport…a peak wind gust to 59 mph from the west.

Continue reading July 8 to July 14 – This Week in Denver Weather History

July 1 to July 7 – This Week in Denver Weather History

This Week In Denver Weather History
July 1 to July 7 - This Week in Denver Weather History

As Colorado seems intent on starting a potentially record-setting streak of hot days, we see similar streaks in our look back at this week in Denver weather history. Also notable are the number of lightning and hail events that have injured, killed and caused extensive damage.

From the National Weather Service

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

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.

30-1

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.

1

In 1915…northeast winds sustained to 41 mph with gusts to 50 mph occurred just before a thundershower in the evening. Rainfall was only 0.07 inch.

In 1941…unusually heavy thunderstorm rains flooded basements and blocked traffic. Water was curb high on many downtown streets. The thunderstorm also pelted the city with hail of unknown size. Rainfall in downtown Denver totaled 0.72 inch…but greater amounts likely occurred in other parts of the city.

In 1960…a severe dust devil moving through an Adams County suburban area blew over a fireworks stand…injuring an 11- year-old boy customer and two women operators of the stand. The boy was found under the demolished stand 100 feet away.

In 1961…hail as large as 1 1/4 inches in diameter was reported over east Denver.

In 1967…golf ball size hail fell over portions of metro Denver. Hail stones to 2 inches in diameter damaged roofs and broke windows in northeast Boulder. Marble to golf ball size hail fell at the Boulder airport. A funnel cloud was sighted over the foothills near Boulder. Hail stones of 1 to 2 inches in diameter were measured at Jefferson County Airport near Broomfield. Marble size hail fell in the vicinity of Arvada and Westminster.

In 1982…severe thunderstorms dropped large hail in Denver… Boulder…Commerce City…Lakewood…Wheat Ridge…Golden…and Arvada. Most locations reported hail size from 3/4 to 1 1/4 inches in diameter.

In 1990…the high temperature reached 102 degrees at Stapleton International Airport.

In 1998…hail to 1 1/2 inches in diameter fell near Bennett.

In 2001…the temperature climbed to a high of 101 degrees at Denver International Airport.

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.

Continue reading July 1 to July 7 – This Week in Denver Weather History

Denver sets 24 hour precipitation record for July 13; Closes in on top 10 wettest Julys

Record Rain
Denver easily broke the 24 hour precipitation record for July 13th.

It is readily apparent that July has thus far been a wet month given that we have seen eight straight days of thunderstorms.  Yesterday the storms set a record for precipitation and Denver is on pace to make the month one of the wettest Julys on record.

Out at Denver International Airport yesterday, 1.03” of precipitation was recorded.  This set the record for the date easily besting the old record of 0.45” set in 1993.

Here in Thornton we recorded 0.45” yesterday so a good bit less than out at the airport but still a decent shot of precipitation.

This brings Denver’s official total to 3.19” for the month so far. Average for the entire month of July is 2.16” so we are far ahead of that.

Number 10 on the ‘top 10 wettest Julys’ occurred in 1985 with 3.71”.  Given the fact that the forecast continues to contain daily thunderstorms for the foreseeable future, there is a good chance we will exceed that before the month is over.

Thornton is ahead of the game in comparison to DIA as we have recorded 4.52” so far this month.