This week in weather history we really begin to see the arrival of monsoon season and the heavy rains and flooding it can bring to the Thornton and Denver area. Be sure to check out the events on the 23rd and what the heavy rain brought to the Thornton area in 2004.
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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 1934…a streak of 15 consecutive days of 90 degrees ranked 5th on the list of hot streaks. The record of 24 consecutive days was established in the summer of 2008.
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In 2008…a streak of 26 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.
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In 2003…heavy rain producing thunderstorms caused flash flooding across southern metro Denver. Automated rain gages measured 2 to 3 inches of rain in less than an hour. The heavy rainfall caused many intersections and underpasses to flood…stranding motorists. Sections of I-25 and I-225 were closed due to the high water.
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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.
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In 1875…recent heavy rains produced high waters on many creeks and rivers in the area…which threatened the destruction of property at some locations. Cherry Creek in the city was running the highest in 10 years. Heavy rain in the mining regions over the last 2 days resulted in water running “everywhere” and the suspension of some work.
In 1881…a thunderstorm passing across the city produced lightning with no rain. A woman was seriously injured when struck by lightning several blocks from the weather office in downtown Denver.
In 1934…the temperature reached a high of 100 degrees in downtown Denver.
In 1965…hail…rain…and lightning hit west metro Denver. Hail stones as large as 1 1/2 inches in diameter accumulated to a depth of 2 inches in Evergreen where 2.95 inches of rain in 2 hours caused some flooding in the business section of the town. Lightning caused some power outages.
In 1973…two funnel clouds were observed 5 miles southeast of Littleton. The same funnel clouds were observed for 20 minutes…5 miles west and 5 miles west-southwest of Arapahoe County airport…now Centennial Airport.
In 1975…lightning injured a man in Denver and caused power outages in Aurora…Lakewood…Westminster…and west Denver.
In 1984…strong thunderstorm winds gusting to 45 mph shattered 7 large plate glass windows at Stapleton International Airport.
In 1985…a tornado touched down in the surrey ridge area of northern Douglas County…just west of I-25. Ten homes were damaged; one under construction was nearly destroyed. Two vehicles were thrown off I-25 injuring three people. A pick-up truck was thrown 50 feet by the twister. In addition…a cluster of severe thunderstorms pounded all of metro Denver with torrential rain…hail…and wind. The heaviest rain fell in Aurora where one location reported 2.37 inches in just 40 minutes. One location in northeast Aurora received a total of 4.30 inches from the storm. There was extensive street and basement flooding…and a number of roads were damaged or washed out. An Aurora boy suffered minor injuries when he was washed into a drainage ditch. Golf ball size hail in Aurora piled up to 5 inches deep. An inch of rain fell in 20 minutes at Stapleton International Airport…closing it to air traffic for an hour. Up to 1 1/2 inches of rain fell in just 15 minutes over central Denver with the high water closing I-25. The water was so deep on the freeway…that one vehicle was completely submerged and people were diving into the water from the freeway overpass. Three homes in Littleton were damaged by lightning. Wind blew out several windows from a high rise apartment building in southeast Denver. Rainfall totaled 1.51 inches at Stapleton International Airport.
In 1997…torrential rain and damaging hail pummeled eastern sections of metro Denver. Hail up to 1.25 inches in diameter fell at the national weather service office on the site of the former Stapleton International Airport. The hail continued for about 15 minutes and accumulated to a depth of 2 to 3 inches…causing extensive damage to cars in the area. Heavy rainfall totaled 3.83 inches in about an hour from the nearly stationary thunderstorm. Numerous cars stalled along I-70…and several homes were flooded in east Denver. The roof of a building collapsed under the weight of the water. The next day several “fatalities” were discovered near the national weather service office; two prairie dogs were found dead along with three rabbits that either drowned or were killed by the large hail.
In 1999…lightning struck two residences in Littleton…but caused only minor damage. Lightning triggered a fire at a residence in cherry hills village. A small portion of the roof and ceiling were damaged before the fire could be extinguished.
In 2000…hail as large as 1.25 inches in diameter fell near Roggen northeast of Denver.
In 2004…heavy rainfall caused flooding on the Virginia Canyon Road near Idaho Springs…which had to be closed for repairs.
In 2006…the temperature climbed to a high of 100 degrees. The high temperature was not a record maximum for the date.
In 2007…a severe thunderstorm produced large hail…up to 1 inch in diameter…about 6 miles north of Northglenn.
In 2016…two men at the Indian Tree Golf Course in Arvada were struck by lightning when they sought shelter from a rapidly developing thunderstorm under a tree. One man died from his injuries while the other suffered minor injuries. Very heavy rainfall was observed across central and southern parts of Denver. The storm dropped around 1.5 inches of rainfall in 30 minutes and caused minor street flooding. Nickel size hail was reported west of Pine in central Jefferson County.
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In 2005…the high temperature climbed above 100 degrees on each of the 5 days with readings of 101 on the 19th…105 on the 20th…104 on the 21st…and 102 on both the 22nd and 23rd. A new record maximum temperature for the month of July of 105 degrees was set on the 20th…which also equaled the all time record maximum for Denver of 105 degrees first set on august 8th in 1878. Daily maximum temperature records were set on each day…and the 5 day period equaled the record for the most consecutive days of 100 degrees or more first set from July 4th through 8th in 1989. The intense heat resulted in a high use of electricity for cooling purposes. The demand for electric power exceeded the supply and rolling black-outs… Each lasting about an hour…were scheduled across metro Denver during the afternoons and early evenings.
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In 1898…an apparent thunderstorm produced sustained northwest winds to 45 mph with gusts to 51 mph.
In 1939…the high temperature reached 102 degrees in downtown Denver. This was the highest temperature recorded since august 8…1878…a period of 61 years…and the third highest temperature of record at the time. Six miles to the east… At Denver municipal airport…the maximum temperature reached 104 degrees. A dry period during mid-July…combined with low relative humidities…resulted in an unusually large number of forest fires in the mountains west of Denver.
In 1941…an afternoon thunderstorm caused two lightning deaths. The men were struck by lightning near the Denver airport.
In 1951…a thunderstorm wind gust to 54 mph was recorded at Stapleton Airport.
In 1965…heavy rain west of Denver damaged roads and bridges. Two bridges in Golden were washed out. Lightning in Denver caused some power failures and fires…mostly in the northeast section of the city. Heavy rain caused street flooding in the city of Denver. Hail as large as 1/2 inch in diameter and 0.40 inch of rain in 5 minutes were measured at Stapleton International Airport where precipitation totaled 1.09 inches. Lightning damaged a house in Littleton…and caused a power outage in idaho springs.
In 1973…lightning damage was reported west of Arvada.
In 1975…heavy rains caused flash flooding across metro Denver…resulting in the closing of several streets and damage to numerous homes and businesses. Hail 1/2 to 3/4 inch in diameter was reported.
In 1976…heavy thunderstorms caused flooding of streets in southeast Denver and western Arapahoe counties. A total of 3.35 inches of rain was measured at Kassler southwest of Littleton.
In 1978…a girl was injured by lightning at a country club southwest of Denver.
In 1984…heavy rain was reported just east of Buckley Field in Aurora where 1.15 inches fell in just 45 minutes.
In 1986…thunderstorms dumped heavy rain across metro Denver causing extensive street flooding…power outages…and basement flooding. The greatest recorded rainfall was 4.39 inches in Lakewood. In extreme northwest Denver…2.29 inches of rain fell in just 20 minutes. Arvada was drenched with 2.60 inches of rain…and over an inch fell in southeast Denver and adjacent sections of Aurora.
In 1990…heavy thunderstorm rains caused flash flooding in sections of Littleton where 1.20 inches of rain fell in less than 30 minutes. The deluge caused dry creek to jump its banks…causing damage to residential streets…curbs…and sidewalks. Nearly 100 vehicles were stranded for a time in fender-deep water when sewers and drainage ditches became choked with debris. The heavy runoff submerged many Littleton streets and intersections.
In 1992…strong thunderstorms moved slowly through east metro Denver…producing rainfall up to 2.50 inches in a short time. Weather spotters reported 0.75 to 1.00 inch of rain in less than 30 minutes. Many areas of southeast Denver were flooded…including I-25 where up to 6 feet of water filled some underpasses. Hail to 3/4 inch in diameter fell in Aurora.
In 1995…a tornado touched down briefly in an open field near Strasburg. Thunderstorm winds gusted to 58 mph at Centennial Airport.
In 1996…strong thunderstorm winds damaged the building of a telephone installation company in the city of Denver.
In 1998…the high temperature reached 100 degrees at Denver International Airport.
In 2006…heavy rainfall in the overland wildfire burn area caused minor flash flooding in Jamestown. The roads behind the Jamestown fire hall were washed out…when a culvert was blocked by debris. A rockslide was also reported in town.
In 2009…a severe thunderstorm produced damaging winds… Large hail and very heavy rain across the western and southern suburbs of Denver. Widespread damage was observed in the cities of Arvada…Lakewood and Wheat Ridge. The intense straightline winds were the result of a wet microburst which downed hundreds of trees and snapped power poles. Wind gusts to 80 mph were reported along with hail up to 1 3/4 inches in diameter. The combination of wind and hail caused widespread damage to homes and vehicles. The damage claim estimates totaled 350 million dollars; about 32900 claims were filed for homes…while another 19500 claims were filed for vehicles. As many as 90000 homes and businesses were left without power. In some areas it took up to 3 days to completely restore electrical service. Minor injuries were reported from broken glass during the storm…but no one was hospitalized. The storm crippled the computers at the Colorado crime information center in Lakewood for nearly 3 hours. One weak tornado touched down near Parker but did no damage. In southern weld County… Severe thunderstorms produced widespread damage over 150 square miles of farmland. In all…400 farms were directly impacted by severe weather. Damage to crops alone was estimated to 3 million dollars. At Denver International Airport…a peak wind gust to 48 mph was observed from the northeast. In addition…1.01 inches was measured at the airport.
In 2013…severe thunderstorms produced large hail… Ranging in size from nickel to golf ball…across portions of Arapahoe… Denver…Elbert and Weld counties. In addition… Damaging wind gusts to 60 mph snapped large tree branches in Thornton and 3 miles west-southwest of Buckley AFB. In Bennett…hail up to 1 1/2 inches in diameter was reported. At Denver International Airport…a peak wind gust to 58 mph was recorded from the northeast.
In 2017…a severe thunderstorm north of Elizabeth produced hail up to 1 inch in diameter. The hail completely covered the ground.
20-23 Continue reading July 19 to July 25: This week in Denver weather history →
