In our July weather preview we discussed how the month is not only Denver’s hottest but also its stormiest. Our look back at this week in Denver weather history helps to illustrate that fact. We start seeing 100+ degree days as well as many of the types of fast moving thunderstorm events expected this time of year.
From the National Weather Service:
29-15
In 2000…the 29th marked the beginning of a near record hot streak for metro Denver. The high temperatures…as recorded at Denver International Airport…exceeded the 90 degree mark for 17 consecutive days from June 29th through July 15th. The record of 24 consecutive 90 degree or above days was set from July 13th through August 5th…2008.
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In 1874…a streak of 18 consecutive days of 90 degrees tied for second with another streak that was later set in the summer of 1901. The record of 24 consecutive days was established in the summer of 2008.
1-31
In 2012…it was the hottest July on record in Denver since weather records began in 1872. The average temperature for the month was 78.9 degrees which was 4.7 degrees above normal. There were 27 days in which the high temperature equaled or exceeded 90 degrees…which established a new record. There were also 7 days in which the temperature equaled or exceeded 100 degrees which tied the record set in 2005.
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In 1874…the temperature climbed to a high of 101 degrees in downtown Denver.
In 1881…the all time highest recorded daily minimum temperature of 77 degrees occurred in the city. This was also the highest daily minimum temperature ever recorded in July.
In 1885…a severe thunderstorm produced hail the size of hazel nuts…which fell with great force. A telegraph pole in west Denver was struck by lightning and shattered to pieces.
In 1955…a brief microburst wind gust to 61 mph was recorded at Stapleton Airport.
In 1960…a major hail storm caused 1.5 million dollars in damage across metro Denver. The heaviest damage occurred in south Denver…Englewood…Littleton…and Golden from wind- driven hail as large as golf balls and heavy rain which caused flooding. Winds were estimated at 60 to 70 mph. Rainfall was estimated at 2 to 3 inches. Hail accumulated 3 to 4 inches deep in some sections. Hail carried by flood waters drifted 3 to 4 feet deep. An Englewood policeman was injured when hail broke the windshield of his car. One inch of rain in 10 minutes…and heavy hail damage were reported in Parker. At some places the hail from the storm was still on the ground the next morning.
In 1967…large hail stones from 1 3/4 to 2 1/2 inches in diameter damaged cars and buildings in southwest Denver and Littleton where hail drifted to depths of 3 to 4 feet. The hail caused a great deal of damage…and streets were flooded by heavy rain over many sections of west metro Denver. At centennial race track near Littleton…a few hail stones were as large as tennis balls. Large hail broke the windshield on a Littleton police car. Golf ball to tennis ball size hail fell in the vicinity of Arapahoe road and south Broadway. One inch diameter hail fell at the intersection of orchard and south university. Golf ball size hail fell in Broomfield. Hail in Westminster was measured from 1 to 1 1/4 inches in diameter. Tornadoes were sighted by the public near Cheery Creek Reservoir… north of Commerce City…and in Arvada…but caused no reportable damage.
In 1993…high winds developed behind a strong cold front along portions of the Front Range. While the strongest winds were reported north of metro Denver…the winds blew out a half inch thick pane of glass from a vacant 9-story building. The glass landed on a parked car below. West winds gusting to 52 mph kicked up some blowing dust at Stapleton International Airport.
In 1996…lightning sparked a small fire near buffalo creek in southern Jefferson County. Only one acre burned before the fire was contained.
In 2002…heavy thunderstorm rain washed out a frontage road 6 miles north of Larkspur. The nearby mountain ranch subdivision was also flooded. Heavy rainfall in the Hayman fire burn area washed out a secondary road when debris from the runoff blocked a culvert. Hail as large as 3/4 inch fell near Keenesburg…in Castle Rock…and 7 miles to the south of Castle Rock.
In 2005…severe thunderstorms produced high winds. Wind gusts to 75 mph were measured near Longmont and to 60 mph just west of Boulder. No damage was reported.
In 2007…severe thunderstorms produced large hail in the foothills and suburbs west of Denver. Large hail from 1 to 2 inches in diameter was reported in the vicinity of Idaho Springs…Rollins and Edgewater.
In 2009…severe thunderstorms produced large hail and north and east of Denver. Hail up to one inch in diameter was observed near Erie and firestone. Hail up to 1 3/4 inches was observed 5 to 6 miles west-southwest of Byers. The golfball size hail caused extensive damage to a wheat field. In Aurora…six children received minor injuries when lightning struck a nearby tree. The injuries occurred when they were knocked down by the blast. None of the children suffered burns or appeared to have been directly hit by lightning.
In 2014…a severe thunderstorm produced large… up to 1 ½ inches in diameter…about 14 miles northwest of Golden.
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In 1874…the temperature reached a high of 102 degrees in downtown Denver. Large forest fires in the mountains from the west-northwest to the south filled the atmosphere over the city with dense smoke.
In 1885…a thunderstorm produced sustained winds to 44 mph with gusts to 60 mph. A circus tent was tattered by the strong winds.
In 1900…a thunderstorm produced northwest winds sustained to 42 mph with gusts to 51 mph…but only 0.05 inch of rain.
In 1903…the all time lowest temperature ever recorded in July…42 degrees…occurred. The temperature also occurred on July 31…1873.
In 1910…thunderstorm winds were sustained to 42 mph from the southwest.
In 1922…thunderstorm winds were sustained to 37 mph with gusts to 48 mph.
In 1956…a thunderstorm wind gust to 54 mph was recorded at Stapleton Airport.
In 1964…several men were knocked down by a bolt of lightning while playing golf in south metro Denver. They got up and ran for cover when one of them was struck by a second bolt. He suffered burns and shock.
In 1987…a weak tornado was observed for 6 minutes…7 miles northeast of Watkins. Hail 3/4 to 1 1/4 inches in diameter fell in southeast Aurora.
In 1988…lightning struck a group of people at the Jefferson County fairgrounds. A 42-year-old woman was seriously injured and was hospitalized for 3 days. Four other people sustained minor injuries.
In 1993…strong northwest winds uprooted several trees across metro Denver. Wind gusts to 64 mph were reported at Erie north of Denver. A west wind gust to 43 mph was recorded at Stapleton International Airport.
In 1995…lightning struck and injured two people standing in a field in Arvada.
In 1998…heavy thunderstorm rain…up to 2.75 inches…and marble size hail combined to flood local roads and fields near Roggen.
In 2002…heavy thunderstorm rain in the Hayman fire burn area caused flash flooding. In Jefferson County…Gulch Road was washed out. In Douglas County…high water washed out some forest access roads as well…generally to the east of a line extending from signal butte to Deckers.
In 2010…intense thunderstorms produced torrential rainfall… In excess of 5 inches in one hour…and caused flash flooding in the vicinity of Elizabeth. Numerous County roads were washed out. The combination of heavy rain and hail made it necessary to run snow plows through town. Extensive basement flooding was also reported. Severe thunderstorms produced large hail from Aurora south to Elizabeth and Larkspur. The hail size ranged from 1 to 2 inches in diameter. A wet microburst produced 1.84 inches of rainfall at Denver International Airport. A peak wind gust to 48 mph was also observed from the northeast.
In 2017…a microburst produced a wind gust to 61 mph…about 13 miles east-northeast of Denver International Airport.
In 2019…severe thunderstorms brought a wave of large hail across portions of Arapahoe…Broomfield…Denver…Douglas…Jefferson… and Weld counties. The hail ranged in size from 1 to 2 inches in diameter. The city of Lone Tree evacuated Sweetwater Park… where Fourth of July celebrations were underway…and Brighton delayed its Fourth of July concert. The Denver Outlaws game was postponed due to lightning. In Denver County…there was widespread damage from the hail…including damage to roof coverings and vehicles.
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In 1875…nearly every railroad running into the city was damaged by heavy thunderstorm rains. The heavy rains washed out wooden bridges over normally dry creeks. Some trains were entirely suspended. In the city…heavy thunderstorm rain totaled 1.05 inches on the 4th…but only 0.28 inch on the 5th.
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In 1989…one of the most intense heat waves on record roasted metro Denver. The temperature reached 100 degrees or more on 5 consecutive days. The city had previously never recorded more than 2 straight 100-degree days since records began in 1872. Water and electricity usage reached all time highs. The heat wave created extremely dry weather conditions…which contributed to a major forest fire in Boulder canyon on July 9th. The temperature reached 103 degrees on the 8th…and the mercury climbed to 101 degrees on both the 4th and 5th…and to 102 degrees on both the 6th and 7th. The low temperature of 68 degrees on the 8th equaled the record high minimum for the date.
5 Continue reading July 3 to July 9: This Week in Denver Weather History