June is when Colorado sees the majority of its severe weather and our look back at this week in Denver weather history highlights this fact. Many occurrences of damaging and deadly lightning, powerful winds, large hail and of course tornadoes are seen.

From the National Weather Service:

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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.

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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.

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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.

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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 Broomield. Minor damage to the roof was observed.

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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.

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In 1921…heavy rainfall for nearly a week…on top of streams already swollen by mountain snowmelt…produced widespread flooding over the South Platte River basin…including the tributaries through the canyons to the west and southwest of Denver. Heavy rainfall over the 6-day period totaled 3.36 inches in Boulder…4.98 inches in Morrison…4.27 inches in Castle Rock…and 2.94 inches in the city of Denver. Rainfall amounts in the foothills were estimated between 3 and 6 inches. The narrow-gage tracks of the Colorado and southern railroad were destroyed in the Platte Canyon. From the mouth of the canyon through the city to near Brighton… The river spread from 1/2 to nearly 1 1/2 miles wide… Flooding farm and pasture land and destroying or damaging many bridges. In the city…many businesses along with as many as 500 homes were inundated…forcing their evacuation. Bridges were swept away. The high waters flooded the rail yards and stock yards in lower downtown…closing three adjacent packing houses. The heavy rains also caused flooding on Boulder creek in Boulder on the 6th.

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

In 1961…torrential rains fell 10 to 30 miles north of Denver…causing flooding in the town of Frederick. The rush of water broke through and over a retaining dike sending a 5-foot wall of water into the town…flooding homes and damaging sewer lines…roads…and streets. Golf ball size hail fell in derby…west Denver…and Lakewood…causing more than one million dollars in damage.

In 1981…severe thunderstorms produced tornadoes over metro Denver. The first tornado touched down at the intersection of Alameda Ave. and Sheridan Blvd. The twister moved north along Sheridan Blvd….damaging businesses…apartment buildings…homes…and vehicles. Over ten homes were unroofed. The roof of one landed in the middle of a neighborhood park. At least 10 mobile homes were wrecked. The tornado curved to the northeast into northwest Denver… Hopping up and down in several places. Very strong winds outside the actual funnel caused 20 to 30 thousand dollars in damage in downtown Denver. The third floor of one old building was demolished. No major injuries were reported from the tornado…although several people were hurt slightly in traffic accidents on Sheridan Blvd. In the confusion caused by the storm. Damage in Lakewood alone was estimated at 200 thousand dollars. At the same time… The worst tornado to ever hit metro Denver struck Thornton. Coming from the same thunderstorm that spawned the Denver twister…the Thornton tornado tore a swath through the heart of the city. 87 homes were destroyed…110 others damaged at least moderately. In all…600 homes in a 100 block area sustained some damage. The twister also hit shopping centers…several restaurants…and other buildings. Seven of the 42 injured were considered serious. The storm was strong enough to snap lamp posts in half and drive a 6- inch slab of wood 2 feet into the ground. Damage was estimated at up to 50 million dollars. The same storm that struck Thornton produced another damaging tornado that touched down in the northwest section of Fort Lupton. This twister damaged 16 homes and numerous cars and campers. Two children were slightly injured when the car they were in was knocked about and its windows shattered by the storm. The twister also damaged two commercial buildings. Damage was very spotty…and observers said the storm hopped up and down at least 3 times. Dollar damage was estimated at 500 thousand dollars. The thunderstorm complex that produced 3 damaging tornadoes also dropped large hail which damaged many cars over northwest Denver. One to 2 inches of rain fell in less than an hour…flooding a mobile home park with 3 to 4 feet of water on the northwest edge of Denver. The high water damaged about half of the 392 homes in the park. Local flooding was also reported in other areas across metro Denver. A tornado was also sighted near Franktown…but caused no damage. A thunderstorm wind gust to 52 mph was recorded at Stapleton International Airport.

In 1982…a cold air funnel cloud touched down briefly in southwest Denver. Two tornadoes were briefly spotted near Watkins. No damage was reported from these storms. A brief funnel cloud was sighted by national weather service observers at Stapleton International Airport where 1/4 inch hail fell.

In 1984…there were several sightings of tornadoes around Parker. No damage was reported.

In 1985…a tornado just southeast of Aurora was spotted by a national weather service employee. No damage was reported. Severe thunderstorms pummeled the metro area with hail. One inch to baseball size hail was reported in south Lakewood…one inch hail in Littleton…3/4 inch to 1 inch hail in Aurora…and golf ball size hail in south Denver.

In 1989…hail up to golf ball size fell over Arvada. A golf course had to be evacuated as the hail accumulated up to 3 inches deep in some places. One inch diameter hail fell in west Denver and Westminster.

In 1993…an early morning thunderstorm produced lightning… Which caused an attic fire at a residence in Niwot northeast of Boulder. Damage was estimated at 40 thousand dollars. No one was injured.

In 1994…hail to 1 1/2 inch diameter fell just northeast of Boulder. One inch diameter hail fell in Golden. Thunderstorm wind gusts to 70 mph were recorded in erie.

In 1995…a tornado was sighted over open country near Strasburg. No damage was reported. A funnel cloud was sighted 11 miles east of Aurora where 3/4 inch hail fell.

In 2001…severe thunderstorms produced large hail over east and southeast metro Denver. Hail as large as 1 3/4 inches in diameter fell at Centennial Airport with 1 1/2 inch hail near Buckley Field…1 1/4 inch hail in Parker…1 inch hail near Elizabeth…7/8 inch hail at Cheery Creek Reservoir…and 3/4 inch hail 20 miles north of Kiowa in Elbert County.

In 2002…severe thunderstorms dumped large hail across metro Denver. Hail to 1 3/4 inches in diameter fell over southeast Denver and 4 miles north of Aurora. Hail to 1 1/4 inches pelted Parker. One inch hail was measured near Ft. Lupton…and 3/4 inch hail fell 9 miles southeast of Buckley Field…near Strasburg…and at the site of the former Stapleton International Airport.

In 2005…thunderstorms producing heavy rain and hail caused flash flooding over parts of southeast metro Denver. People became trapped in their vehicles by the high water… And numerous water rescues were required. The hardest hit areas included the vicinity of I-25 and Alameda Avenue…as well as the intersection of Yale Avenue and Quebec Street. Several basements were flooded along Eastman Place. Severe thunderstorms brought heavy rain and hail to eastern Centennial and southeastern Aurora. Up to 3 feet of standing water was reported on east orchard road where several motorists were stranded in their vehicles and needed to be rescued. Hail to 3/4 inch in diameter fell in the area. Ten vehicles were stranded on Grand Avenue…and most had to be towed once the floodwaters receded. Water was reportedly chest deep at one location on Girard Avenue. Hail as large as 3/4 inch in diameter also was reported in Littleton…near Parker…and near Buckley Air Force Base. Hail to 7/8 inch was measured near Sheridan and Cheery Creek Reservoir.

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In 1904…a thunderstorm during the early morning of the 3rd turned into widespread general rain…which continued into the early afternoon of the 4th. Rainfall totaled 2.04 inches.

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In 1878…a “waterspout” or cloudburst of rain was sighted up the South Platte canyon at around noon. The resulting high waters on the South Platte River slightly damaged a railroad bridge in the city.

In 1937…a trace of snow fell in downtown Denver where rainfall totaled 0.25 inch. Minimum temperature of 34 degrees was a record low for the date. Northeast winds were sustained to 22 mph.

In 1951…the start of the second shortest snow-free period on record…109 days…occurred with the last snow of the season…a trace…on the 3rd. The first snow of the next season occurred on September 21st when 4.2 inches of snow fell at Stapleton Airport.

In 1954…a microburst produced brief sustained winds of 40 mph with gusts as high as 64 mph at Stapleton Airport.

In 1956…the failure of the Georgetown dam caused downstream flooding on clear creek at Idaho Springs and Golden.

In 1976…funnel clouds were sighted near Brighton…Erie…and Dacono…all north of Denver. A tornado touched down briefly 1 1/2 miles east of Lafayette. Another tornado touched down briefly at Hyland Hills Golf Course in Westminster. No damage was reported.

In 1983…severe thunderstorms during the afternoon produced 3/4 inch hail in south Denver…golf ball size hail 5 miles west of Parker…1 1/4 inch hail in Littleton…1 1/2 inch hail in south Aurora.

In 2001…hail as large as 1 inch in diameter fell 17 miles north of Bennett in Adams County.

In 2005…snow was mixed with rain for nearly an hour at Denver International Airport during mid to late morning. The temperature at the time was 45 degrees. Precipitation totaled 0.36 inch for the day. Northwest winds gusted to 37 mph.

In 2008…a severe thunderstorm produced large hail…up to 1 3/4 inches in diameter in Arvada…a northwest suburb of Denver. Several vehicles were damaged. In addition…a severe thunderstorms produced hail to 1 inch in diameter… 10 miles northeast of manila…east of Denver International Airport.

In 2015…severe thunderstorms broke out across Boulder… Denver…Elbert…Jefferson and southern Larimer Counties. Two large and long lived tornadoes developed near Berthoud and near Simla. The tornado that occurred along the Boulder and Larimer county line.  It first touched about 3 miles south of Berthoud…and then tracked to the west/northwest and lifted about 6 miles southwest of Berthoud. The majority of the damage was EF1…with some areas of EF2… and a few small areas of EF3. At least 25 homes between Longmont and Berthoud were damaged; three of them destroyed. No injuries were reported as the winds tore apart homes and rolled vehicles. The EF3 rating is defined as maximum winds estimated at 135 to 140 mph. The path length was 6 miles long with a width of one quarter mile at times. Large hail from quarter to tennis tennis ball size was observed.  The largest hail occurred in northeast Boulder County. The hail damaged cars and homes; breaking windows and windshields.  In addition… numerous roads were closed along the Larimer and Boulder county line due to flash flooding. Just west of Berthoud… 3.47 inches of rain had fallen.  At Denver International Airport…only 0.01 inches of rainfall was recorded… with a peak wind gust to 35 mph from the northeast.

In 2020…severe thunderstorms produced intense wind gusts across parts of Adams and Denver counties. A peak wind gust of 64 mph was observed near Bennett…with a gust to 58 mph observed at Denver International Airport.

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In 1965…lightning and an 18-hour rain storm damaged streets and roads and telephone and power lines across metro Denver. Precipitation totaled 2.77 inches at Stapleton International Airport where the visibility was reduced to 3 miles at times from pre-frontal thunderstorms and heavy upslope rains.

In 1998…a late season snow storm struck the Front Range foothills. Up to 5 inches of snow fell in Coal Creek Canyon. Light snow also fell over western sections of metro Denver and briefly at Denver International Airport. Snow covered the grass at the Denver federal center in Lakewood before melting around mid-morning on the 5th. No snow fell at the site of the former Stapleton International Airport. Several temperature records were set. High temperatures of 47 degrees on the 4th and 49 degrees on the 5th were record low maximums for their respective dates. Minimum temperature of 34 degrees on both the 5th and 6th were record lows for those dates.

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In 1864…high water on the west fork of clear creek caused a small dam near empire to fail…which destroyed several downstream bridges.

In 1885…a windstorm during the afternoon and early evening produced south to southwest winds at sustained speeds up to 42 mph.

In 1937…a trace of snow fell in downtown Denver. This was the latest snowfall of record at the time. Light rain and snow were mixed around mid-day. Precipitation totaled only 0.01 inch. North winds were sustained to 20 mph.

In 1941…hail of unknown size fell on the city.

In 1961…lightning struck and injured an airman outside a base classroom at Lowry Air Force Base. Funnel clouds were sighted near Frederick and firestone north of Denver. The one near Frederick briefly touched down in an open field but caused no damage. Heavy rain and hail hit the Fort Lupton area causing damage to crops. Heavy rain in Frederick added to the flood damage of the 3rd. A pilot reported a funnel cloud that touched down briefly and then dissipated south of Castle Rock.

In 1965…a lightning-caused fire destroyed a mountain home near Rollinsville.

In 1988…a tornado touched down 5 miles east of Lafayette near I-25 and stayed on the ground for 15 minutes. The twister hit a campground…demolishing one trailer and damaging six others…along with 4 cars. The rope-like funnel also blew down fences…signs…and electrical boxes. The twister moved a 1500-pound hay wagon 150 feet. Total damage to the campground was estimated at 50 thousand dollars. Another tornado touched down between Broomfield and Lafayette…staying on the ground for about 20 minutes. The twister hit a subdivision…unroofing one abandoned house and causing minor damage to a dozen others. A four- car garage and three barns were destroyed. At one location a chain link fence…a satellite dish…and a shed were destroyed…while the deck and garage of the house were damaged. A grain storage tank was moved 200 feet. There were reports of boards being blown through walls; one came through a kitchen.

In 1992…lightning struck a 15-year-old boy…causing minor injuries…in Adams County 6 miles north-northeast of Stapleton International Airport. Thunderstorm winds gusted to 63 mph at Jefferson County Airport near Broomfield…to 58 mph at the U.S. Atomic Energy Commission’s facility at Rocky Flats…to 58 mph in Thornton…and to 48 mph at Stapleton International Airport where 1/8 inch diameter hail fell.

In 1996…strong microburst winds up to 60 mph damaged several trees in Boulder…snapping large branches 1 to 2 inches in diameter.

In 1997…a woman was struck by lightning as she was walking to her car in Nederland. The lightning bolt apparently struck a nearby power line and arced into her left hand. She received minor injuries.

In 2014…severe thunderstorms broke out across parts of Arapahoe…Douglas…Elbert and Jefferson Counties… impacting areas generally southwest and south of Denver. The storms produced large hail…from quarter to golfball size.

In 2015…severe thunderstorms produced hail up to 1 1/2 inches in diameter in Castle Rock and hail up to 1 inches in diameter…southwest of Byers.  At Denver International Airport…0.99 inches of rainfall was recorded. A peak wind gust to 35 mph from the southwest as also observed.

In 2017…an intense thunderstorm produced damaging downburst  winds which snapped a power pole near the interchange of  Interstate 70 and US 36.  A weak short-lived landspout  also touched down south of I-70 near Bennett and tossed  around some lawn furniture.

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In 1977…lightning caused several power outages and moderate damage to a railroad building.

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In 1954…thunderstorm winds at speeds of 50 mph with gusts as high as 59 mph briefly reduced the visibility to 1 mile in blowing dust at Stapleton Airport.

In 1967…the public reported golf ball to 1 3/4 inch diameter hail in the city…3 miles west-southwest of Stapleton International Airport. The amount of damage was unknown. Thunderstorm winds gusted to 46 mph at Stapleton International Airport.

In 1981…hail to 3/4 inch in diameter was reported in east Denver.

In 1990…golf ball size hail was reported near Strasburg on I-70 east of Denver.

In 1991…a tornado was spotted by national weather service personnel and weather spotters…14 to 17 miles northeast of Stapleton International Airport. A funnel cloud was sighted over south Aurora just east of Buckley Field…and a tornado was spotted just east of Watkins. No damage was reported. Thunderstorms moved through Aurora and dropped hail up to 1 inch in diameter. The storms also produced heavy rain… Up to 1 inch in 30 minutes…causing flooding of streets. Water was reported hood deep…stranding motorists. Water covered fire hydrants at some intersections.

In 1995…a waterspout sighted over Standley Lake in northern Jefferson County…quickly dissipated once it reached shore. A brief tornado…which was momentarily visible by a dust debris cloud on the ground…damaged the roof of a house in Westminster. A funnel cloud was sighted just south of Lafayette. Hail from 3/4 to 1 1/4 inches in diameter fell over north Boulder. Thunderstorm outflow produced north wind gusts to 44 mph at Denver International Airport.

In 1997…a tornado touched down near baseline reservoir just east of Boulder. The tornado struck a home…tearing off part of the roof. A storage building nearby was nearly leveled and 5 trees were uprooted. The twister then moved onto baseline reservoir…forming a huge waterspout. Several recreational vehicles and a boat dock were also damaged. A nearly stationary line of thunderstorms dumped 4.60 inches of rain on portions of Thornton. Extensive flooding of streets and underpasses and other low lying areas was reported. Several businesses were flooded and basements in the area were damaged. Rainfall totaled 1.02 inches at Denver International Airport and 1.24 inches at the site of the former Stapleton International Airport. Large hail…up to 1 3/4 inches in diameter…fell over the city of Denver with 3/4 inch hail measured in Littleton and near Henderson.

In 1999…high winds developed for a brief time in and near the foothills of Boulder. The Gamow Tower on the University of Colorado campus recorded a wind gust to 87 mph. Winds peaked to 71 mph atop Niwot Ridge near the Continental Divide west of Boulder.

In 2003…a small tornado touched down near Strasburg…but did no damage.

In 2016…powerful thunderstorms fired up along the Urban Corridor and produced damaging hail…strong outflow winds… heavy rain and lightning. Golf-ball size hail in Highlands Ranch caused extensive damage including broken windows on homes and windshields on vehicles. Heavy rainfall…also produced street flooding. In and around Highlands Ranch… anywhere from 2.3 to 2.8 inches of rainfall was observed… with 1 to 1.5 inches around metro Denver.  At Denver International Airport…0.38 inches of rainfall was recorded.

In 2020…a combination of an upper level trough moving northwest across the state…coupled with a strong surface pressure gradient…led to numerous reports of high wind gusts across the Denver the surrounding region. Most of the wind damage occurred with the passage of a rare derecho; a large fast-moving complex of thunderstorms with powerful straight-line winds. In addition…strong wind gusts from 59 to 71 mph not associated with the derecho… occurred prior to and following the passage of this system. By midday the derecho…moved over the mountains…and then rapidly northeast across the I-25 corridor by mid afternoon. Wind gusts from 60 to 80 mph were common with a few gusts exceeding 90 mph. The highest gust observed was 110 mph…at the Winter Park Ski area…around 12000 feet. Xcel Energy reported more than 208000 customers lost power because of the storm statewide. Widespread tree damage was reported. The intense wind toppled a billboard that crashed onto Denver bakery. Two delivery trucks parked nearby were heavily damaged. Two injuries occurred in Denver…one seriously. A man and his nine-year-old daughter were injured by a fallen tree. They were standing in front of a family members house when the incident occurred. The tree impaled the father through his back and he required several surgeries. His daughter sustained cuts and bruises that required stitches. Southwest winds gusted to 78 mph at Denver International Airport…with a peak gust to 76 mph at Centennial Airport.

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In 2004…a brief hot spell produced 3 temperature records. High temperatures of 95 degrees on the 6th and 98 degrees on the 7th were record maximum temperatures for the dates. Low temperature of 68 degrees on the 7th was a record high minimum for the date.

In 2007…an unusually strong storm system brought very strong winds to the Front Range foothills and urban corridor. Peak gusts included: 92 mph at Boulder…85 mph…2 miles southwest of Boulder…83 mph…10 miles south of Boulder and 55 mph at Denver International Airport. High winds forced the closure of Mt. Evans Road and Trail Ridge Road. Several trees were uprooted across the urban corridor. In Aurora… The driver of a car was injured when some building material blew off the Fitzsimmons complex. The debris landed on the car and knocked the driver unconscious. The wind forced the cancellation of 60 flights at Denver International Airport. Xcel reported outages in Boulder…Denver…Lakewood and Longmont.

In 2012…severe thunderstorms broke late in the evening on the 6th and continued into the 7th…striking areas hardest from Denver southward. Locations impacted by the storms included but were not limited to: Aurora…Castle Rock…Centennial… Highlands Ranch…Lone Tree…Parker and Surrey Ridge. The storms produced a barrage of large hail…damaging straight line winds…flash flooding and several short lived tornadoes. The hail ranged in size from 1 to 2 inches in diameter…and caused extensive damage to homes and automobiles. The hail inundated the roadways with several inches of hail in Douglas County. Consequently…snow plows had to be called out to clear the roadways. The combination of torrential hail and heavy rain produced flash flooding in parts of Elbert…Douglas and Arapahoe Counties…as thunderstorms brought up to 3.35 inches of rain to some areas within 90 minutes. In Aurora…Picadilly Road was closed from flooding north of 6th Avenue. A water rescue took place on South Gun Club Road in Arapahoe County…where floodwaters were rushing to depth of 3 feet. Flash flooding forced the closure of several streets and roads from Parker south to The Pinery… where the floodwaters inundated the roadway with up to 2 feet in several locations.  At Centennial Airport…a historic B-17 Flying Fortress suffered extensive damage as hailstones as large as ping pong balls struck the aircraft. Although the airframe itself did not require repair…the fabric- covered ailerons and elevators were extensively damaged. The hail came straight down and punched holes in the fabric- covered control surfaces. The aircraft landed just hours before the storm hit to participate in a weekend tour stop. Lightning also struck two homes…one in Lakewood and the other in Parker. Straight line winds downed trees and power lines in Aurora. As a result…scattered electrical outages affected around five thousand residents.  At Denver International Airport…0.61 inches rainfall was recorded along with a peak wind gust of 41 mph.

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In 1904…a thunderstorm produced south winds to 40 mph with gusts to 50 mph…but only a trace of rain.

In 1942…heavy thunderstorm rainfall in south Denver caused flooding of shops…stalled motorists…and halted tramway service temporarily. Lightning damaged houses…but there was no loss of life. Precipitation totaled 0.53 inch in downtown Denver.

In 1951…a 24×65 foot roof of a cow barn was lifted off the building and blown to the ground by a “twister” near Fort Lupton.

In 1961…small hail and heavy rain damaged property and crops in southwest metro Denver…including the southwest section of the city…Lakewood…and Littleton. Precipitation totaled 1.20 inch…11 miles southwest of Stapleton Airport. Complete primary and secondary rainbows were sighted by national weather service observers at Stapleton Airport.

In 1968…severe thunderstorms moving to the northeast through sections of Denver caused local flooding of streets and damage to trees and gardens from hail 1/2 to 1 3/4 inches in diameter. One man was killed and 2 were injured at the Wellshire Golf Course when lightning struck a tree under which they had taken shelter. At another golf course… A man was mortally injured by lightning. Marble to golf ball size hail fell over downtown Denver. Hail to 3/4 inch in diameter was measured in Westminster.

In 1975…hail up to 3/4 inch diameter fell in Boulder.

In 1978…a man standing under a tree on a golf course in Denver was struck in the arm by lightning. Wind gusts to 60 mph and golf ball size hail pelted west and south Denver.

In 1986…7/8 inch hail was measured in Lafayette.

In 1990…a thin…rope-shaped tornado touched down east of the intersection of State Highway 2 and 96th avenue just north of the rocky mountain arsenal. No damage was reported.

In 1992…a thunderstorm wind gust to 60 mph was recorded in Boulder. A funnel cloud was sighted by a highway patrol officer just northwest of Stapleton International Airport where thunderstorm winds gusted to 51 mph. Spotters and state patrol officers reported funnel clouds in the northwestern part of metro Denver…near Golden…and 7 miles northwest of Stapleton International Airport.

In 1993…non-convective high winds pummeled the Front Range foothills during the late morning and afternoon. Speeds of 60 to 80 mph were common. The winds caused several power outages as well as uprooting trees. In Lafayette…a 4-year-old boy was slightly injured while standing on the roots of a large tree which was toppled by the winds. The boy fell 10 feet to the ground and was bruised and scraped. A tree fell onto a parked car in Boulder…causing about 35 hundred dollars in damage. West wind gusts to 41 mph were recorded at Stapleton International Airport where a thunderstorm produced 1/8 inch hail at daybreak.

In 1995…severe thunderstorms produced large hail across west and north metro Denver from Golden to Westminster and Fort Lupton. Hail ranged in size from 3/4 to 2 inches in diameter. The largest hail fell in Fort Lupton. A weak tornado produced a brief dust and debris cloud in a corn field 3 miles northeast of Hudson.

In 1997…two plumbers were injured…one critically…when lightning struck a pipe on which they were working in an apartment building under construction in Denver. The bolt apparently hit one man in the hand…passed through his chest…and struck the other worker. The critically injured man…died a few days later. Lightning also injured a man…while he was talking on a telephone in Ward. The bolt passed through the phone line burning his ear.

In 2001…hail as large as 7/8 inch in diameter fell in Westminster.

In 2009…severe thunderstorms in Denver and the surrounding metropolitan area produced five tornadoes… Large hail…up to 3 inches in diameter…and damaging thunderstorm winds. The tornado that produced the most significant damage touched down in southeast Aurora… South of buckley airport; it moved south-southeast across open fields…some residential areas and damaged southlands mall. It was 100 yards wide with a storm track of approximately 5 1/2 miles. Southlands mall had some roof and window damage…as well as wall damage to one of its restaurants. South of the mall…Lowe’s received some roof damage; lightweight sheds and other structures were also destroyed. Numerous homes and apartments suffered window damage…minor roof damage and there were a few broken garage doors. One resident…north of the mall…was injured when he was swept off his porch while attempting to photograph the tornado. He was found unconscious and bleeding in his front yard…with a dislocated shoulder…an injured neck…and numerous other injuries. In addition…the tornado flipped a trailer home. A man inside the trailer suffered minor injuries. In parts of Aurora and Centennial…thunderstorm winds blew down power lines and caused electrical outages. Approximately 8000 homes and businesses were without power for nearly two hours. Earlier in the day…a tornado touched down about 6 miles northwest of Northglenn and caused minor damage. Its path covered approximately 1/2 mile. Several trees were downed in an open field. The tornado also damaged a metal fence and caused minor roof damage to a nearby residence. The third tornado touched down 7 miles east-northeast of Buckley Air Field and flipped a semi-trailer as it passed over Interstate 70. Lastly… Two tornadoes touched down in northwest Elbert County. One tornado damaged several outbuildings…a residence…and downed several trees. In addition… Several horses were injured by flying metal debris. The other tornado touched down in open country. This day was the first in the series of eight to cause damage along the urban corridor. Damage to homes and property along the Front Range totaled $161 million during the 8-day span. The majority of the property damage was caused by hail; 21000 automobile claims and 13000 homeowner claims were filed.

In 2012…severe thunderstorms brought damaging wind and hail…heavy rain and flash flooding.  The storms produced hail from 1.5 to 2.5 inches in diameter. In addition to the large hail…heavy rain from 1 to 2 inches also accompanied the storms. The combination of hail and heavy rain caused extensive street flooding across Aurora…Castle Rock…Centennial…Cherry Creek… Englewood…South Denver…Highlands Ranch…Lakewood and Littleton. The hail was reportedly “knee deep” in several areas making roads impassable. As a result… snow plows had to be summoned to clear the streets. In Castle Rock…a King Soopers supermarket sustained extensive damage when roof partially collapsed under the weight of the hail. At Denver International Airport…0.61 inches of rainfall was again recorded along with a peak wind gust of 40 mph.  Total property damage estimates along the Front Range for the 6th and 7th combined was 321.1 million dollars.

In 2016…large hail up to 1 inch in diameter was observed in Castle Rock.

In 2021…a landspout tornado developed in southwest Weld County…2 miles northeast of Firestone. The tornado traveled north-northeast…and ended 3 miles northwest of Platteville. The tornado reached an intensity of EF-1 on the Enhanced Fujita scale…with estimated wind speeds of 99 mph. There were no injuries…but at least two calves were killed…and several chickens. Other damage included a home located at Highway 66 and Weld County Road 21 that caught fire due to downed power lines. Downed power lines led to a closure of Weld County Road 21 between State Highway 66 and Weld County Road 32.5. The landspout was more than 10000 feet high…and could be seen by spotters as far as 40 miles away. It was on the ground for 35 minutes; it was estimated to be 50 yards wide and traveled a distance of 7.5 miles.

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.

8

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 quarter to half dollar size…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.