With severe weather season in full swing, we see a very eventful week in Denver weather history. Wildfires, amazing hail storms, tornadoes, floods and more all make an appearence on the historical calendar.

1-30

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

11-14

In 1999…damage from several hailstorms in and near metro Denver totaled 35 million dollars. About 17.5 million dollars was from automobile claims with another 17.5 million in homeowner claims. The areas hardest hit by the storms included Castle Rock…Commerce City…evergreen… And Golden.

12-17

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

13-14

In 2006…the high temperature of 99 degrees on the 13th equaled the record maximum temperature for the date first set in 1994. The high temperature of 102 degrees on the 14th was a new record maximum temperature for the date.

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In 1877…an evening thunderstorm produced lightning which struck several houses and killed a cow in the bottom land of the South Platte River

In 1886…hail as large as 3/4 inch in diameter fell in the city. Precipitation was only 0.10 inch.

In 1887…south winds were sustained to 41 mph.

In 1900…a thunderstorm produced northwest winds to 51 mph with gusts to 61 mph…but only a trace of rain.

In 1923…a severe thunderstorm pelted the city with hail. The stones ranged in diameter from 0.2 to 0.8 inch. Gardens and greenhouses suffered considerable damage. Rainfall was only 0.14 inch downtown.

In 1960…one workman was killed and 4 others injured in Lakewood when a partly built apartment building collapsed in strong winds. Microburst wind gusts to 54 mph caused some blowing dust at Stapleton Airport.

In 1967…tornadoes touched down briefly 3 miles west of Franktown and 4 miles northeast of Parker. No damage was reported. Numerous funnel clouds were reported over south metro Denver…one 5 miles south of Denver…one 2 to 3 miles north of Castle Rock…and two near Littleton.

In 1968…a microburst wind gust to 52 mph was recorded at Stapleton International Airport.

In 1972…1 3/4 inch hail was reported in Wheat Ridge.

In 1976…high winds…unusually strong for this late in the season…raked metro Denver. Wind gusts estimated to 100 mph tore 24 boats from their moorings and damaged a total of 47 boats at Boulder reservoir. Wind gusts to 82 mph were recorded in Boulder. The strong winds toppled the wind mast at a radio station in Boulder. An automobile was smashed by a fallen tree in Boulder. Other damage in Boulder was minor…but power outages occurred when tree limbs fell on power lines. At Jefferson County Airport near Broomfield…wind gusts to 78 mph were recorded with 87 mph gusts clocked at rocky flats nuclear plant south of Boulder. Wind gusts to 66 mph were observed in Littleton… And northwest winds gusted to 46 mph at Stapleton International Airport. The strong winds collapsed a barn near Arvada. Several horses received minor injuries. Thirty trees were uprooted or broken in Denver. Four major power outages occurred from west Denver and Lakewood to the foothills.

In 1982…the worst hailstorm in 17 years struck Commerce City. The storm left 4 to 8 inches of hail on the ground. A few of the stones were as large as golf balls. Many vehicles were dented…and some windshields were shattered. Roofs of homes were damaged. Total damage was estimated at over one million dollars. Hail to 1 inch in diameter also fell in Littleton. Only 1/4 inch hail was measured at Stapleton International Airport.

In 1988…lightning ripped a small hole in the roof of a home in the southern part of Boulder. There were some power outages in the area.

In 1992…an off duty national weather service employee reported hail to 1 inch diameter in Westminster.

In 1997…one inch diameter hail fell in Bennett…and 3/4 inch hail was measured in Littleton.

In 1999…hail as large as 1 1/2 inches in diameter hit Aurora. Lightning sparked two small fires at separate residences near the hiwan country club in evergreen.

In 2004…lightning sparked two small fires near Jamestown. One was in geer canyon and the other 7.5 miles up sunshine canyon. Both were quickly contained and caused no damage to structures in the area.

In 2014…severe thunderstorms broke out across the urban corridor. Large hail…ranging in size from 1 to 2 inches in diameter…was observed. The area extended from around Englewood to Aurora and included: Brookridge…Cherry Knolls… Greenwood Village and south Denver. As many as 212 thousand residences were potentially impacted by the storms. The hail shattered windshields and damaged vehicles.

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

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

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

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

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

In 1988…several tornadoes developed across metro Denver. One tornado touched down just northeast of the rocky mountain arsenal. The twister moved very slowly and did no damage…except to demolish a small electrical substation… Even though it was on the ground for nearly 30 minutes. Later…another tornado was sighted east of Brighton about 2 miles north of Barr Lake. An F2 tornado cut a swath through northeast Denver. The main path went through a thickly wooded area for about 6 blocks and uprooted about 500 city owned trees…many of them large elms 75 to 100 years old. Hundreds of privately owned trees were also sucked from the ground by the slow moving twister…which was filmed by a news team in a helicopter as it uprooted trees. The replacement cost to the city owned trees was estimated at 1.5 million dollars. The twister did little damage to buildings. Some homes suffered roof and chimney damage…a gas main was ruptured…and some cars were damaged by falling trees. The uprooted trees also caused curb and sidewalk damage and cut some electrical wires. The funnel cloud passed close to Stapleton International Airport. Aircraft operations were shut down…and the tower was evacuated. The tornado was on the ground for almost 25 minutes. An F3 tornado cut an erratic path through south Denver for about 25 minutes…causing extensive damage in at least 3 areas. The twister damaged about 85 buildings… 20 severely; the total loss was estimated at 5 to 10 million dollars. Many cars were severely damaged; at least 15 vehicles were overturned. One trailer was lifted onto the top of a building that had just been unroofed; numerous antique cars inside the building were damaged. A ford bronco was blown over a church…and landed 100 yards away. A metal storage shed was deposited far above the ground in some power lines. The tornado uprooted many trees on a golf course. No one was seriously hurt…although seven people suffered minor injuries from flying debris. A golfer was thrown 40 feet…but was not hurt; a man clinging to a telephone pole was unscathed…but lost both shoes…a sock…and buttons off his shirt. A woman holding a baby was sucked through a broken convenience store window… But was unhurt. A dog…tethered to the ground by its leash…was suspended in the air by the twister. Uprooted trees crushed cars and damaged curbs and sidewalks. People in downtown Denver could see three tornadoes occurring simultaneously. Hail as large as 1 3/8 inches in diameter fell in extreme southeast Aurora.

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

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

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

15-16

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

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

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

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

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

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

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

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

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

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

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

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

16-17

In 1965…on the afternoon and evening of the 16th…violent thunderstorms produced extremely heavy cloudbursts of rain over the palmer divide and sent a wall of water as high as 20 feet down both branches of plum creek into the South Platte River and through metro Denver. The heavy rainfall produced the most devastating flood in the history of Denver. Rainfall totaled 14.0 inches in 3 hours at both larkspur and palmer lake with 12.0 inches recorded in Castle Rock. The flood waters caused extensive damage to roads and bridges in larkspur…Castle Rock…and Sedalia…including washing out the I-25 bridge over east plum creek in Castle Rock. The citizens of metro Denver received reports of the flooding to the south and had a few hours to initiate evacuation procedures along the South Platte River…greatly limiting the loss of life. By evening…the flood reached Littleton where an heroic effort was made to save nearly 150 horses at the centennial racetrack…which was completely inundated by the flood waters. As the flood proceeded through the city of Denver…the river became more than 1/2 mile wide and destroyed all homes…trailer courts… And businesses in its path. The waters contained debris ranging from refrigerators to old cars. As many as 26 bridges were damaged or destroyed…including the 6th avenue freeway bridge across the South Platte. Both public service company power plants were shut down by the flood. The King Soopers grocery chain bakery was inundated. About midnight… The torrent crested at 25 feet above normal with flow exceeding 40 times normal and is the record flood on the South Platte and many of its tributaries. The flood caused 230 million dollars in damage and 8 deaths along the entire South Platte River basin. The intense rain also caused flooding along Cherry Creek in Denver…on toll gate and sand creeks in east metro Denver…and on Kiowa and Bijou Creeks to the east of Denver. The South Platte River flood closed nearly every major east-west highway into Denver…nearly isolating the city. The flood caused heavy damage to state and County roads in the area. Railroads were also hard hit with the main yards in lower downtown inundated. Sewerage… Water supply facilities…and irrigation works also received heavy flood damage. The flood crest did not reach Nebraska until the 20th.

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In 1915…northwest winds were sustained to 41 mph with an extreme velocity to 42 mph.

In 1967…this was the 24th consecutive day with a trace or more of precipitation from May 25th. Precipitation totaled 5.87 inches during the period…more than a third of the average yearly total.

In 1975…hail more than 2 inches in diameter fell in eastern Aurora.

In 1977…golf ball size hail was reported 3 miles east of Arapahoe County airport…now centennial airport. Heavy hail to 3/4 inch in diameter was reported in Littleton… Castle Rock…and Sedalia.

In 1979…a man and a girl were struck and killed by lightning while walking in a park in northwest Denver.

In 1987…3/4 inch hail fell near Boulder.

In 1991…a microburst wind gust to 59 mph kicked up some blowing dust at Stapleton International Airport.

In 1998…hail as large as 3/4 inch in diameter fell in Boulder.

In 2003…lightning struck a feeder line…knocking out the electricity to about 3000 residents in Littleton. A lightning strike caused minor damage to the roof and attic of a home in Lafayette. Another lightning strike caused minor roof damage to a residence in Louisville. Yet another lightning strike hit a home in Denver and caused a small attic fire. Hail as large as 1 inch in diameter was measured near centennial airport and near greenland.

17-18

In 1964…high winds at speeds of 50 to 60 mph with gusts as high as 75 mph caused damage to homes…power lines…and trees in Boulder. Non-convective west winds gusting to 46 mph caused some blowing dust at Stapleton International Airport on the 17th.

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In 1875…a windstorm produced sustained winds to 45 mph during the morning hours. Numerous forest fires along the base of the mountains were visible from the city.

In 1886…northwest winds sustained to 40 mph were the strongest of the month that year.

In 1987…severe thunderstorms produced lightning…large hail… A tornado…heavy rain…and strong winds across metro Denver. Rainfall totaled 2.50 inches in an hour in wheat ridge… Causing minor flooding. I-25 was flooded in north-central Denver…snarling traffic. Hail 7/8 inch in diameter fell in Louisville with 1 1/2 inch hail near Golden and 1 to 1 3/4 inch hail in and near Castle Rock. A tornado touched down briefly in Castle Rock. No damage was reported. Lightning started a small fire that burned half a cabin near evergreen.

In 1994…a funnel cloud was sighted over Aurora; hail to 1 3/4 inch diameter fell near Brighton; and hail over an inch in diameter fell over Aurora…southeast Denver… Louisville…and Boulder. Lightning struck a home in Henderson 9 miles north of Denver and knocked a hole in the roof…which caused the ceiling to collapse. Hail to 1 1/4 inch diameter was measured at Stapleton International Airport.

In 2002…the Hayman Wildfire in the foothills to the southwest of Denver intensified…and the winds aloft carried the smoke plume directly over metro Denver…again creating a dense haze of smoke which blocked the sun. Surface visibilities were again reduced to as low as 1 1/4 miles at Denver International Airport.

In 2004…severe thunderstorms produced hail to 3/4 inch in diameter near Morrison…in Littleton…near conifer…near Castle Rock…and in Aurora near Cherry Creek.

In 2013…a landspout tornado touched down at DIA. The tornado sent 10 thousand travelers on the concourse…on planes and in the terminal scrambling to get into tornado shelters. The tornado formed just to the south of runway 35r and then moved slowly northwest between runway 35r and 35l…and moved to within one third of a mile of concourses A and B before dissipating. The tornado moved extremely close if not over the ASOS (automated surface observation system) and another low level wind shear sensor at DIA. The ASOS weather observing system reported a 97 mph wind gust…while the wind shear sensor reported a wind gust to 109 mph at the same time indicative of an ef1 tornado. There was only minor damage noted to the equipment. Nine flights were diverted elsewhere during a tornado warning. Severe thunderstorms also produced large hail up to quarter size in Adams and Weld counties.

In 2014…a severe thunderstorm produced large hail up to quarter size near Buckley Air Force Base. At Denver international Airport…a peak wind gust to 55 mph was observed from the southwest…along with 0.37 inches of water.

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In 1874…during the afternoon…large columns of smoke from extensive fires in the mountain forests moved over the city from the west and southwest.

In 1875…while no precipitation was measured in the city… Rainfall over the palmer divide caused Cherry Creek to rise to the highest level in 10 years.

In 1977…hail up to 2 inch diameter damaged two patrol cars in Castle Rock.

In 1983 golf ball size hail fell just north of Bennett.

In 1990…lightning from a thunderstorm struck the roof of a house in south Boulder. Residents of the house were able to extinguish the ensuing fire with a garden hose…but not before several shingles had burned.

In 1992…thunderstorms produced hail up to 2 inches in diameter in central Douglas County near Castle Rock. Hail was 3 inches deep on I-25 south of Castle Rock. A funnel cloud was sighted near Parker.

In 1997…a 66-year-old man was knocked unconscious by a bolt of lightning while he was golfing at the eagle country club in Broomfield.

In 2000…dry microburst winds gusting to near 70 mph were reported across southeast Boulder and northern Jefferson counties. Peak wind gusts included: 68 mph at the national wind technology center…67 mph at Jefferson County airport… And 65 mph in Broomfield.

In 2001…severe thunderstorms produced large hail in the foothills southwest of Denver. Hail as large as 1 3/4 inch in diameter fell near conifer and bailey.

In 2002…lightning damaged the evergreen fire protection district radio repeater. One microwave transmitter…the main fire channel transmitter…and two solar panel controllers were destroyed. Lightning struck a garage and caused a small fire. Two vehicles parked in the garage were damaged. Hail to 3/4 inch in diameter fell near Castle Rock.

In 2004…severe thunderstorms produced hail to 3/4 inch in diameter near Castle Rock…Larkspur…and Golden.

19-21

In 1875…smoke from several large forest fires in the mountains was visible from the city on each of these days.

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In 1888…northwest winds were sustained to 44 mph.

In 1956…a microburst caused a brief wind gust to 58 mph at Stapleton Airport.

In 1964…hail up to 1 inch in diameter was reported 1 mile north of Stapleton International Airport. A 3 minute hail storm at both Stapleton International Airport and Lowry Field piled small hail to one half inch deep.

In 1967…a strong thunderstorm dumped 1.95 inches of rain in less than an hour at Stapleton International Airport and produced a wind gust to 54 mph. The storm caused some flooding in east Denver and Aurora. There was widespread flooding to streets…basements…and store buildings and automobiles. Hail stones to 3/4 inch in diameter were measured at Buckley Field in Aurora. A tornado touched down just south of Littleton…damaging a barn and killing several head of cattle.

In 1985…a wind gust to 61 mph was reported at Golden gate canyon in the foothills west of Denver.

In 1986…a man was killed by lightning at Highlands Ranch south of Denver.

In 1987…several tornadoes were sighted across metro Denver. A tornado touched down briefly 5 miles west of Parker. A tornado was sighted just north of Chatfield Reservoir. A tornado just northwest of Watkins was on the ground for 15 minutes. A tornado near Barr Lake was taped by a television news crew. It had a double vortex and was on the ground for about 10 minutes. In addition to the 4 tornadoes…severe thunderstorms dumped large hail across metro Denver. One inch hail was reported in southeast Aurora; 3/4 inch hail fell at the Denver technology center…Buckley Field…and Franktown.

In 1992…several short-lived tornadoes occurred in the vicinity of Barr Lake. No injuries or damages were reported. A water spout was sighted over the southern end of Barr Lake. Funnel clouds were also sighted on the grounds of the rocky mountain arsenal by national weather service observers at Stapleton International Airport.

In 1994…hail up to dime size covered I-25 south of Denver and near Sedalia. Heavy rain caused local flooding on the interstate highway.

In 1996…strong thunderstorm winds downed several large tree limbs in Boulder on the university of Colorado campus. A stop light in the city was also blown down.

In 1999…lightning sparked an oil tank fire near Brighton.

In 2001…large hail driven by strong thunderstorm winds raked Denver international and Front Range airports. Wind gusting to 54 mph along with hail as large 2 inches in diameter punched at least 14 thousand holes and cracks in the flat roofs of several buildings at Denver International Airport. In addition…93 planes and hundreds of cars were damaged. About 100 flights had to be cancelled…stranding 1500 travelers. The airport was completely shut down for about 20 minutes. The storm also damaged a ground avoidance radar used to track planes on the ground to prevent collisions. Damage was estimated at 10 million dollars…not counting the damage to the 93 airliners. The storm moved south and struck Watkins with hail as large as 2 1/2 inches in diameter and winds gusting to 60 mph. A least 30 private planes at Front Range airport were destroyed. The radome protecting the National Weather Service Doppler radar…which was tracking the storm…also sustained damage. The large hail…damaging winds…and heavy rain pummeled a mobile home park near Watkins. In the park…52 mobile homes…14 recreational vehicles…3 homes…and a commercial building were damaged. Siding was riddled with holes and windows were broken. Vehicles sustained extensive damage and car windows were shattered. A handful of people were treated for minor cuts and bruises. The strong winds also flipped a tractor trailer along I-70 near Watkins. The storm caused power outages…which affected about 1200 residents. Excluding the damage at Denver International Airport…damage estimates totaled 49 million dollars…making the storm the costliest in the last 3 years and the 10th costliest since 1984. A small tornado touched down just east of Brighton… But did no damage. Hail as large as 2 inches in diameter fell near Fort Lupton with 3/4 inch hail measured in Bennett. Precipitation from the storm totaled only 0.23 inch at Denver International Airport.

In 2002…heavy rain fell near the Hayman Wildfire burn area. Flash flooding washed out a 40-foot section of the access road to Cheeseman Reservoir. Some debris was washed against a gate…blocking the road. Hail to 1 1/2 inches in diameter fell near central city with 3/4 inch hail near Blackhawk.

In 2003…hail as large as 1 inch in diameter fell near Bennett and Strasburg with 3/4 inch hail measured in Denver…Golden… At Centennial Airport…and near Parker. Hail as large as 7/8 inch was reported in Arvada.

In 2004…a severe thunderstorm produced hail to 3/4 inch in diameter in and near Brighton.

In 2005…severe thunderstorms produced large hail near the palmer divide. Hail to 1 inch in diameter was measured near larkspur with 7/8 inch hail near Sedalia and 3/4 inch hail in Greenland. An apparent thunderstorm outflow produced a wind gust to 59 mph at Denver International Airport during the evening hours.

In 2010…lightning struck a home in centennial and sparked a fire which caused extensive damage.

20-21

In 1897…high winds raked the city overnight. Southeast winds were sustained to 60 mph with gusts as high as 72 mph on the 20th. Southeast winds were sustained to 57 mph with gusts to 60 mph on the 21st.

In 2007…a brief hot spell produced two temperature records. The high temperature of 97 degrees was tied on the 20th. A new record high temperature of 99 degrees was established on the 21st.