How does 42 degrees sound right about now? That mark is one of the highlights of this week in Denver weather history. It was the low temperature recorded twice in our past and the coldest July temperature on record. Many more notable events have also occurred.
From the National Weather Service:
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.
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.
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.
In 1873…the all-time lowest recorded temperature in July… 42 degrees…occurred. The same temperature also occurred on July 4…1903.
In 1874…during the late afternoon rain and hail fell for 5 minutes followed by brief heavy rain. Pieces of solid ice of irregular shape fell upon the roof of the station. The hail stones measured 1 1/2 inches in diameter. Precipitation (rain and melted hail) was only 0.16 inch.
In 1889…the high temperature climbed to 100 degrees in downtown Denver.
In 1919…heavy thunderstorm rainfall totaled 2.59 inches in downtown Denver during the evening. Rainfall was 1.90 inches in an hour…a new record at that time.
In 1961…over an inch of rain in a short period of time caused flooding of streets and basements in Denver. Rainfall totaled 1.30 inches at 11th and Lincoln in central Denver.
In 1964…the temperature reached 91 degrees in Denver…making this the 27th day of the month that the temperature reached 90 degrees or more. This is the all time record for 90 degree days in a month in Denver.
In 1972…one inch diameter hail fell in Hudson northeast of Denver.
In 1976…during the evening hours extremely heavy thunderstorm rains produced flash flooding in Big Thompson Canyon which killed 144 people between Estes Park and Loveland. No significant weather occurred in metro Denver at the time.
In 1987…1 inch diameter hail fell in Lakewood and 3/4 inch hail fell near Louisville. Southeast Boulder County was drenched with 1.25 inches of rain in just 20 minutes.
In 1993…thunderstorm winds damaged a chimney of a home near Parker.
In 1996…a weak tornado (f0) was sighted 12 miles east of Denver International Airport. No damage was reported.
In 1998…heavy monsoonal thunderstorm rain triggered a mud slide in Blackhawk. The mudslide blocked Main St. and caused an estimated half million dollars in damage to a casino. Heavy thunderstorm rain…up to 3 inches in an hour…caused a flash flood along Buffalo Creek. Portions of County Road 126 just south of the town of Buffalo Creek were washed out. The flood waters nearly washed away the bridge as mud and debris slammed into the structure. Hail to 1 3/4 inches in diameter fell near Idaho Springs.
In 2004…severe thunderstorm winds toppled a 65-foot blue spruce tree in Parker. The tree landed on a home damaging the roof and gutters. The downed tree poked dozens of holes into the shingles.
In 2013…severe thunderstorm winds… with gusts estimated to 80 mph…downed power poles which caused scattered outages in and around Byers…Bennett and Strasburg. Some property damage was also observed. Near Byers…aluminum siding and roofing was peeled off sheds. Large hail…up to one inch in diameter… was reported north of Bennett. At Denver International Airport…a peak wind gust to 40 mph was observed from the northeast.
In 1888…heavy rain in the mountains and foothills caused flooding on clear creek in Golden. The high waters also washed away portions of the railroad tracks in the canyon between Idaho Springs and Golden.
In 1901…the temperature reached a high of 100 degrees in the city.
In 1902…the high temperature climbed to 100 degrees in downtown Denver.
In 1914…a thunderstorm produced 1.00 inch of rainfall in just 21 minutes and north winds sustained at 43 mph with gusts to 50 mph. Rainfall totaled 1.17 inches.
In 1938…the temperature climbed to a high of 100 degrees in downtown Denver…which is the record maximum for the date. The temperature was also recorded on this date in previous years.
In 1976…flight operations at Stapleton International Airport were suspended for 90 minutes when the airport tower radar was knocked out and water reached a foot deep on some taxi ramps after 1.50 inches of rain fell in one hour. Heavy rain also caused minor flooding in east Denver and Aurora where lightning damaged the roof of a home and injured the owner. One young man was swept down a flooded ditch…but was rescued by firemen. A number of rafts were floated in flooded streets. Thunderstorm rainfall totaled 1.71 inches at Stapleton International Airport.
In 1978…a tornado damaged a house and broke a power pole 5 miles northwest of Parker. A microburst wind gust to 52 mph briefly reduced visibility to 1 mile in blowing dust at Stapleton International Airport.
In 1985…heavy thunderstorms roared through the southern and western sections of metro Denver…producing large hail and heavy rain. Lightning hit a recreational vehicle trailer causing it to burn. There was a lot of street flooding over western suburbs where rainfall totaled over 2 inches in some areas. One inch diameter hail was reported in Littleton and near Evergreen. Hail piled 4 to 6 inches deep at Tinytown in the foothills southwest of Denver.
In 1990…a small rope-like tornado was spotted in open country 15 miles southeast of centennial airport. No damage was reported from the twister.
In 1992…pilots reported a funnel cloud near the construction site of the new Denver International Airport. A few minutes later…a tornado was reported near Bennett. The tornado remained on the ground for about 18 minutes and was visible from the national weather service office at Stapleton International Airport. Thunderstorm wind gusts to 70 mph were reported near Bennett and Watkins with a wind gust to 60 mph at Brighton. Two men were injured when struck by lightning. A young man sustained serious injuries when struck by lightning while jet skiing on Cheery Creek Reservoir. A man received only minor injuries when struck by lightning while golfing in Westminster.
In 1994…heavy thunderstorm rains in the foothills west of Denver caused the closure of the Virginia Canyon Road north of Idaho Springs by rocks and debris.
In 2001…a 34 year old man on the South Platte River bike path in Denver received minor injuries when lightning struck a nearby tree. Lightning…coupled with strong thunderstorm winds…knocked out electrical power to about 10 thousand homes and businesses in Golden.
In 2006…strong thunderstorms hit southern metro Denver. A severe thunderstorm wind gust estimated to 71 mph knocked down a tree in Aurora near Cherry Creek. Lightning sparked a fire in a home near lone tree and struck a transformer at an RTD light rail station at Interstate 25 and Yosemite Street. Heavy thunderstorm rainfall forced the closure of Arapahoe Road between Holly and Quebec streets due to high water. Flooding was also reported near Park Meadows Mall and Greenwood Village. Heavy rainfall also caused flooding in Highlands Ranch…lone tree…and Parker. Water up to 6 inches deep was reportedly running over the roads.
In 2020…a worsening drought that started in the spring of 2020…continued through August. The month of August tied with 2011 for the warmest August on record. It also occurred in the middle of the second warmest summer on record. The combination of hot and dry conditions…in addition to critically dry fuels from years of beetle kill…resulted massive wildfires. The Cameron Peak fire…which became the largest wildfire in the state`s history started on August 13th and continued to burn into October. Smoke from this wildfire in addition to several other large wildfires in Colorado and the West resulted in multiple days of extremely poor air quality. In addition…the air quality in Denver and the entire Front Range had deteriorated severely due to the very warm temperatures and high ozone content… which had spiked significantly. In August…26 days in the month equaled or exceeded 90 degrees.
In 1878…the high temperature reached 100 degrees in downtown Denver.
In 1911…an apparent dry microburst produced sustained west winds to 42 mph.
In 1972…one workman was killed and another injured when a strong gust of wind destroyed a partially completed apartment building in south Denver. Hail to 1 3/4 inch diameter fell in Golden.
In 1973…hail to 3/4 inch diameter was reported in Boulder.
In 1986…a major outbreak of severe thunderstorms occurred along the Front Range. Thunderstorms developed explosively. Some places were hit by large hail twice. Two inch diameter hail broke car windows on I-25 west of Brighton…and up to 1 1/4 inch hail broke windows in Thornton. Baseball size hail damaged several planes near Watkins. Funnel clouds were sighted around Aurora. Hail over 1/2 inch in diameter covered the ground 3 to 4 inches deep at Hudson northeast of Denver. Most of the hail fell north of metro Denver…but 3/4 inch diameter hail was measured at Stapleton International Airport. Total damage from the hail storms this day was estimated at over 10 million dollars.
In 1991…late afternoon thunderstorms produced heavy rain across metro Denver. Two feet of water covered parts of I-25 in southeast Denver…while one foot of water covered parts of U.S. Highway 285 in Englewood. Thunderstorm rainfall totaled 0.50 inch at Stapleton International Airport.
In 2001…severe thunderstorms producing heavy rain and hail… Either washed out or damaged several County roads in the Watkins and Bennett areas. A small tornado (f0) touched down near Bennett…but did no damage. Hail as large as 1 3/4 inches in diameter fell near Watkins. One inch diameter hail was measured near Hudson and Keenesburg.
In 2008…strong winds blew several trees down in Denver… Damaging homes and downing power lines. A peak wind gust of 67 mph occurred at Centennial airport…with gusts to 60 mph estimated in Denver. A peak wind gust of 37 mph was measured at Denver International Airport. An elderly man was killed when a wind damaged tree broke free and crushed him while he attempted to remove it. The downed power lines caused outages to about 500 Xcel Energy customers.
In 1876…grasshoppers were in great abundance in the city and caused considerable damage to gardens and to crops in the surrounding farms and ranches.
In 1951…heavy thunderstorms rumbled across metro Denver through the night. Heavy rain totaled 3.45 inches at Stapleton Airport. This was the greatest 24 hour precipitation ever recorded during the month of August in Denver.
In 2007…heavy rain caused localized flash flooding near Ft. Lupton. Up to 8 inches of water was reported across County road 18.
In addition…several other County roads in the immediate area were washed out.
In 1878…the high temperature climbed to 100 degrees in downtown Denver.
In 1900…a thunderstorm produced west winds sustained to 48 mph with gusts to 55 mph…but only a trace of rain.
In 1903…a thunderstorm produced a trace of rainfall and northwest winds sustained to 45 mph with gusts to 60 mph. The high temperature was 99 degrees.
In 1927…a thunderstorm produced hail and sustained north winds to 22 mph.
In 1933…heavy cloudburst rains caused the failure of the Castlewood dam…which resulted in flash flooding on Cherry Creek…the deaths of 7 people in Denver…and flood damage estimated at 1 million dollars. Lower Denver was flooded during the morning by waters pouring down Cherry Creek and its valley from Castlewood Dam…which had broken between midnight and 2:00 am. Heavy rain of 3 to 9 inches in 9 hours in the watershed above the dam resulted in the failure. At 7:30 am…the flow in Cherry Creek was reported at 16 thousand second-feet as compared with a peak flow of 3 thousand second-feet in other years. The flood waters ruined hundreds of acres of crops and drowned scores of farm animals. Six bridges in Denver were swept away. Great deposits of mud were left in the lower sections of the city…including hundreds of basements and lower floors of buildings. At the end of the month…a deadly stench still rose from swampy areas near the lower city limits.
In 1963…heavy thunderstorm rains in the Parker area caused Cherry Creek to overflow…which damaged roads.
In 1985…a tornado touched down briefly about 10 miles northeast of Parker. No damage was reported.
In 1991…upslope northeast winds produced chilly temperature readings and heavy rain across metro Denver. Rainfall… With no thunder…totaled 1.56 inches at Stapleton International Airport where the heavy rain briefly reduced the surface visibility to 7/8 mile. The mercury climbed to a high of only 63 degrees.
In 1992…a thunderstorm wind gust to 64 mph was recorded in Brighton. A wind gust to 60 mph was measured near the construction site of the new Denver International Airport. Lightning started a fire in an Evergreen church…causing over 75 thousand dollars in damage.
In 1998…3/4 inch hail fell in Jefferson County 15 miles northwest of Arvada.
In 2006…heavy thunderstorm rainfall caused flash flooding along Leyden Creek in unincorporated Jefferson County. An automated rain gauge on upper Leyden Creek…6 miles northwest of Arvada…measured 2.68 inches of rainfall in less than 2 hours. Two to three feet of water covered the roadway at the intersection of 82nd and Quaker Street.
In 2009…a woman riding her bike…in training for an ironman triathlon…was struck by lightning in Boulder. She was in the 78th mile of a 100-mile training ride when she was hit. The woman lost her vision initially and couldn’t move her arms. After a short stay in the hospital…she made of complete recovery.
In 2013…severe wet microburst thunderstorms produced damaging winds and very heavy rain in and around Buckley Air Force Base…Erie and Lafayette. Peak gusts included: 68 mph in Erie…61 mph at Buckley AFB… and 60 mph in Broomfield…4 miles east-southeast of Erie and Lafayette. In Erie…a velodrom under construction was heavily damaged by heavy rain and high winds. The wind toppled the eastern third of the 250-meter cycling track. Bolts measuring one-half-inch thick by 7 1/2 inches in length were ripped out of concrete footers while 16-inch-wide trusses…collapsed under the force of the wind. In town…heavy rain… around 2.5 inches in less than one hour…caused extensive street flooding. The intense wind also downed trees which resulted in localized power outages. In addition…an empty semi-trailer was blown on its side. A weak non supercell tornado touched down briefly in an open field…7 miles northwest of Hudson. The storm forced seven incoming flights at Denver International Airport to be diverted and contributed to 45-minute delays for others. At Denver International Airport…a peak wind gust of 55 mph was observed from the northeast…with 0.66 inches of rainfall recorded. The very heavy rain produced flash flooding in part of Aurora. Road closures were set up in both directions on both Picadilly Road and Gun Club Road…just north of Buckley AFB. A man had to be rescued when his car was trapped in flood waters at the intersection of 6th Ave. and Picadilly Road. Flash Flooding was also observed at the junction of E-470 and I-70 with water running over the road.
In 2018…a gust front associated with a dissipating thunderstorm moved out of the foothills of Boulder and northern Jefferson counties continued to push eastward into Denver. The storm knocked down trees and branches. Power lines were also damaged which produced scattered outages. Peak wind gusts included: 67 mph near Gold Hill…64 mph in south Boulder…62 mph at Rocky Mountain Metropolitan Airport…and 60 mph at Denver International Airport.
In 1988…two inches of rain fell in 3 hours at both Morrison and wheat ridge. Thunderstorm rainfall totaled 0.80 inch overnight at Stapleton International Airport.
In 1889…southwest winds were sustained to 42 mph with an extreme velocity to 52 mph.
In 1924…0.01 inch of rain fell over downtown Denver. This along with the 0.01 inch of rainfall on the 10th was the only rainfall of the month…the driest August on record.
In 1963…heavy rains in the foothills above Idaho Springs caused mud and rock slides which closed U.S. Highways 6 and 40 for a time.
In 1976…hail to 1 inch diameter was reported 12 miles southwest of Denver. Hail to 3/4 inch in diameter was reported in Lakewood. Small hail…1/4 to 1/2 inch in diameter…fell at Stapleton International Airport.
In 1982…heavy rain poured through the roof of a clothing store in Aurora…causing widespread water damage. The roof was being repaired when the storm hit.
In 1983…hail up to one inch in diameter fell in Aurora where heavy rain produced street flooding.
In 1984…a Colorado state trooper was struck and injured by lightning in Northglenn.
In 1989…a microburst wind gust to 52 mph was recorded at Stapleton International Airport.
In 1997…lightning sparked a small fire in a home in Arvada… Causing minor damage. Several intersections in both Arvada and Westminster were flooded by thunderstorms producing heavy rain. Several cars were damaged by the high waters… And a number of businesses were flooded.
In 1999…flooding and flash flooding problems developed over metro Denver as slow moving thunderstorms dumped from 2 to 3.5 inches of rainfall in about 3 hours. Near the junction of I-25 and U.S. Highway 36…up to 4 feet of water flooded an auto dealership. About 45 cars were ruined. Damage estimates to the dealership alone totaled nearly a half million dollars. Sections of I-25 and U.S. 36 near the interchange were closed due to floodwaters. Floodwaters… Up to 5 feet deep…forced the evacuation of two mobile home parks in Federal Heights. Railroad tracks were washed out near Federal Blvd. and 64th Avenue. Numerous power outages caused widespread blackouts in Thornton and Littleton. Along Massey Draw near Carr St. and Chatfield Reservoir…4 homes were flood damaged and portions of their backyards washed out. Widespread street flooding was also reported in Boulder where several buildings were flood damaged…including the University of Colorado memorial center.
In 2004…two golfers were shocked when lightning struck the eighth green of the golf course at Castle Pines north of Castle Rock. The two men suffered only minor injuries. Heavy thunderstorm rain from the same storm caused flash flooding. Floodwaters rushed across parts of U.S. Highway 85 near the entrance to the Castle Pines Golf Club. The traffic lanes were covered with up to 6 inches of running water.
In 2008…lightning sparked a grassfire that consumed 300 acres on the northern edge of Green Mountain…in Jefferson County. Gusty winds and very dry conditions allowed the wildfire to quickly spread and threaten several houses. Fortunately…only minor damage was reported to homes due to smoke and melted siding.
In 2018 a severe thunderstorm produced strong winds in and around Denver. A peak wind gust to 60 mph was observed near Firestone with a gust to 59 mph near Buckley Air Force Base. A peak wind gust to 40 mph from the southwest was observed at Denver International Airport.
In 1881…the low temperature cooled to only 76 degrees…the record high minimum temperature for the month.
In 1889…southwest winds were sustained to 42 mph.
In 1918…hail pelted the city…but was light and caused no damage. Precipitation totaled 0.25 inch. Northwest winds were sustained to 31 mph.
In 1964…lightning struck two boys in Denver while playing ball. One was treated and released from the hospital…but the other boy suffered second degree electrical shock and cardiac arrest and was hospitalized in critical condition for several days.
In 1969…two tornadoes touched down briefly in an open field southeast of Buckley Field in Aurora. No damage was reported.
In 1970…heavy rain in the Indian Hills area in the foothills west of Denver caused flash flooding…which washed out roads and damaged other property. Hail accumulated to a 3 inch depth with stones up to golf ball size; however…most of the damage was from flooding.
In 1982…2.38 inches of rain fell in an hour in Arvada… Causing minor flooding on Ralston Creek.
In Westminster… 1 1/2 inches of rain fell…causing damage to streets and culverts.
In addition…lightning caused some minor power outages across metro Denver.
In 1983…very heavy thunderstorms hit the southern portion of metro Denver. Heavy rainfall…as much as 2.89 inches in 38 minutes…caused widespread street flooding in southeast Denver. Two feet of water covered a section of I-25. Hail up to golf ball size accompanied the storm in Littleton and Englewood…along with 60 mph winds.
In 1984…a heavy thunderstorm drenched Littleton with up to 2.35 inches of rain in an hour…along with small hail that piled up to 2 inches deep. Flood waters were up to 4 feet deep in parts of town with many basements flooded. There were some power outages caused by lightning.
In 1990…a thunderstorm dumped 1.25 inches of rain in 12 minutes near tower and smoky hill roads in southeast Aurora. Minor street flooding was reported in the area.
In 1992…a pilot reported two funnel clouds near Cheery Creek Reservoir. Both dissipated quickly. Dime size hail fell near Franktown.
In 1994…one inch diameter hail fell near Strasburg. No damage was reported.
In 1999…a dog kennel east of Denver International Airport… Was flooded when a small dam…upstream in Elbert County… Was breached. The floodwaters…up to 4 feet deep…washed away some 6-foot fences and other small buildings. Ten of the 70 dogs boarded at the kennel drowned.
In 2002…a mail carrier was struck by lightning as he inserted a key into a multi-unit mailbox in Bailey. The shock knocked the man back against the mail truck. He suffered minor injuries. Lightning struck a residence in Commerce City. The resulting fire destroyed the roof of a detached garage and damaged much of its contents. Hail as large as 1 3/4 inches in diameter pelted pine. One inch diameter hail fell in Arvada and southwest Denver. Heavy rain triggered a mudslide along U.S. Highway 285 near Bailey. Both lanes of traffic had to be closed until debris could be removed from the highway. Several residences in the Bailey and Glenisle areas were also flooded.
In 2004…heavy thunderstorm rainfall caused localized flash flooding in Virginia Canyon near Idaho Springs. Sections of the Virginia Canyon Road had to be closed due to the floodwaters.
In 2008…a severe thunderstorm produced large hail…up to 1 1/4 inches in diameter…northeast of Parker. Several automobiles were damaged.
In 1877…a severe rain…hail…and wind storm struck Denver. The storm produced a one minute sustained wind speed of 75 mph. Rainfall totaled 1.00 inch in 25 minutes. The hail storm damaged vegetable gardens in the city.
In 1954…an unconfirmed tornado was reported in Westminster. A funnel cloud was sighted in the area…but it was not certain if it had touched down. No damage was reported.
In 1980…the temperature reached 100 degrees…setting a new record high for the date.
In 1982…3/4 inch diameter hail was reported in north Denver. Heavy rain caused street flooding in central Denver where 4 to 5 feet of water inundated I-25…closing the freeway for a while. Rainfall across metro Denver ranged up to 2.35 inches in just over an hour. An estimated 2000 basements were flooded. Only 0.01 inch of rain fell at Stapleton International Airport.
In 1991…heavy rain caused flooding at the junction of I-25 and I-70. Dime size hail was reported northeast of Boulder near Niwot.
In 1995…microburst winds gusting as high as 58 mph caused minor damage to an apartment complex in Broomfield. Some homes under construction were also damaged when the winds knocked over 2 by 4 wood beams along with some insulation and roofing materials…which broke a few windows. Microburst winds also overturned a camper near Barr Lake.
In 1996…hail ranging in size from 1 to 1 1/2 inches fell near Bennett.
In 2001…3/4 inch hail fell in the foothills near Conifer.
In 2008…a record daily rainfall record was set at Denver International Airport. The record of 1.29 inches in 24 hours broke the previous record of 1.10 inches set in 1929.
In 2020…a severe thunderstorm developed near Byers. The wind snapped large tree branches…up to 4 inches in diameter…and produce large hail up to one inch in diameter. At Denver International Airport…a peak wind gust to 47 mph was observed from the west.