Our look back at this week in Denver weather history reminds us that severe weather can continue to strike, even during what is normally a relatively calm month. Lightning, hail and flooding are three continuous threats as we see during our look back at history this week.
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. This was one day short of equaling the all time record. The record of 18 consecutive 90 degree or above days was first set from July 1st through July 18th…1874. The record was equaled from July 6th through July 23rd…1901.
1-18
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.
4-5
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.
4-8
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
In 1908…a late evening thunderstorm produced sustained north winds to 40 mph…hail…and 0.45 inch of precipitation.
In 1949…a dust devil…possibly a small tornado…was observed 3 miles to the northwest of Stapleton Airport.
In 1973…the temperature reached 100 degrees at Stapleton International Airport.
In 1974…strong thunderstorm winds damaged a mobile home…a barn…two houses…and several sheds near Watkins.
In 1975…a thunderstorm wind gust to 53 mph was recorded at Stapleton International Airport. Hail up to 3/4 inch in diameter fell over the northwest suburbs and in northwest Denver.
In 1977 three houses in Denver were struck by lightning. Some heavy damage and fire occurred.
In 1990…lightning caused minor damage to houses in Castle Rock…Louviers…and Littleton.
In 1996…lightning caused only minor damage when it struck a home in Evergreen. Lightning from a fast moving thunderstorm blasted a large hole in the side of a house in Lakewood. Lightning triggered a minor power outage in the Boulder area. About 200 homes were affected.
In 2001…severe thunderstorm winds gusted to 60 mph at Denver International Airport and to 70 mph…7 miles southwest of the airport.
In 2008…microburst winds downed a large tree and some power lines near a Denver apartment complex. Several of the tenants’ vehicles were damaged.
In 2009…a wet microburst produced very strong winds in and just east of Denver. A peak wind gust of 69 mph was measured 1.5 miles east of Denver. In addition…1.50 inches of rain fell in 30 minutes. A peak wind gust to 68 mph was also observed near byers. Southwest winds gusted to 31 mph at Denver International Airport. The airport also received 0.30 inches of rainfall.
6
In 1876…the high temperature reached 101 degrees in downtown Denver.
In 1943…four people were injured by lightning in Denver during a severe early evening thunderstorm. At least two houses were set on fire by the lightning. One house had 1500 dollars in damage and the other 1000 dollars.
In 1959…wind and lightning caused some damage in metro Denver. Wind gusts to 67 mph blew down power lines…signs… And trees. Lightning struck several transformers…leaving many areas without power.
In 1971…a microburst wind gust to 68 mph was recorded at Stapleton International Airport.
In 1973…the temperature reached a high of 103 degrees. This was the second consecutive day with a temperature of 100 degrees or more.
In 1984…a weak tornado moved through eastern Aurora. About 10 homes sustained minor damage to roofs; some sections of fence were thrown more than a block. Soft hail…an inch in diameter…fell over central Aurora…and 1.35 inches of rain fell in just 45 minutes…5 miles east of Buckley Field. Torrential rain and hail stopped traffic on I-225 in central Aurora for 15 minutes. Street flooding was widespread. A wind gust to 57 mph was recorded in southeast Aurora. A wind gust to 66 mph was reported at Front Range airport near Bennett. Northwest winds gusted to 44 mph at Stapleton International Airport where only 1/8 inch hail fell.
In 1986…one inch diameter hail fell near Conifer in the foothills west of Denver. The storm produced 1.50 inches of rain in an hour with a storm total of 2.15 inches. Nearby buffalo creek was drenched with 0.80 inch of rain in just 10 minutes.
In 1996…3/4 inch diameter hail fell in Bennett…east of Denver. Hail…as large as 1 1/2 inches in diameter… Damaged several vehicles in the parking lot of the Colorado Speedway race track near Dacono north of Denver. Several trees were also damaged.
In 2001…a severe thunderstorm wind gust to 59 mph was recorded at Denver International Airport…along with small hail.
In 2009…hail up to 1 inch in diameter was observed near Longmont.
In 2010…heavy rain caused flash flooding near interstate 70 at the Byers exit. Two feet of water was observed moving across the bottom of exit ramp. One car was washed into a tree but no one was injured. In addition…severe thunderstorms produced hail up to 1 1/2 inches in diameter near Franktown. At Denver International Airport…only 0.01 inches of rainfall was observed. A peak wind gust to 45 mph from the west was also recorded.
7
In 1905…a thunderstorm produced sustained northeast winds to 40 mph…but only a trace of rain.
In 1933…heavy cloudbursts during the afternoon in the Idledale area and on Saw Mill Gulch caused flash flooding on bear creek resulting in 7 deaths. Flooding in Morrison was compounded when a wall of water as high as 15 feet swept down Mount Vernon Creek. The flooding caused extensive damage to the Bear Creek Canyon Highway.
In 1959…wind gusts to 45 mph at Stapleton Airport…but higher in other areas…damaged power lines and buildings and caused widespread minor damage from falling trees and broken limbs. A field house under construction at Adams County High School in Commerce City sustained severe damage.
In 1963…farm buildings east of Boulder were possibly damaged by a small tornado as there were unconfirmed reports of a funnel cloud in the area.
In 1967…a storm of cloudburst proportion caused damage from flooding in southwest and south Denver. Unofficial reports indicated rainfall of 2.00 inches in 30 minutes and more than 3.00 inches total from the storm. Streets and buildings were flooded by the heavy run-off. Hail in some areas contributed to flooding by blocking storm drains. Water accumulated 12 to 14 feet deep in several underpasses and some street intersections. A young woman drowned when she tried to cross a flooded street and was swept off her feet and trapped under a parked car. Water reached a depth of 5 feet in the street. Police rescued numerous stranded motorists. The roof and wall of a flat roofed store building collapsed under the weight of deep water on the roof. Cars were washed over curbs in many areas. In southwest metro Denver…100 to 150 homes were flooded. Hail caused damage in other areas of Denver and in Aurora. Wind toppled trees in several areas. Snowplows were called out to clear hail from some highways and runways at Stapleton International Airport. Lightning damaged trees and power lines and started a fire…which extensively damaged an automobile dealership. Thunderstorm rainfall totaled 0.83 inch at Stapleton International Airport.
In 1981…severe thunderstorms produced 3/4 inch hail over east Denver. About 1 1/2 inches of rain fell in Littleton. Thunderstorm winds gusted to 45 mph at Stapleton International Airport.
In 1983…tennis ball size hail fell about 5 miles north of Boulder; it was soft and caused no damage.
In 1987…a weak tornado touched down in Castle Rock. Several weak tornadoes were observed in the area. No damage was reported.
In 1988…lightning struck a sign at a bank near Louisville… Damaging it and causing a smoldering fire that resulted in smoke damage to the bank and an adjacent building. Heavy thunderstorm rain…accompanied by 1/2 inch diameter hail at Stapleton International Airport…briefly reduced the visibility to 1/4 mile. Rainfall totaled 1.41 inches… But 1.12 inches fell in 32 minutes.
In 2001…severe thunderstorms dumped large hail across north metro Denver. Hail to 1 3/4 inches in diameter fell near Erie with 7/8 inch hail measured in Thornton.
In 2004…a 9-year-old boy was struck by lightning while at a playground in Arvada. The umpire at a nearby baseball game…along with 2 passers-by…administrated CPR and resuscitated the boy who had quit breathing. The boy suffered first and second degree burns…but was released from the hospital in less than 24 hours. A dry microburst over Denver International Airport produced a recorded peak wind gust to 61 mph.
In 2006…up to 3 inches of heavy thunderstorm rainfall in the Hayman Wildfire burn area produced destructive flash flooding along west creek between the towns of Deckers and Westcreek in southwest Douglas County. Horse creek…which drains into west creek…swelled from a normally small creek into a raging torrent…25 to 30 feet deep and 300 feet wide. The wall of water damaged or destroyed about 30 sections of a 5 mile stretch of State Highway 67…which parallels west creek. Several homes were extensively damaged or destroyed. No injuries were reported…but several people had to be rescued…due to extensive damage to access roads and bridges in the area. Reconstruction was estimated at 13.3 million dollars.
In 2011…heavy rain associated with a wet microbursts produced over 3 inches of rain in 90 minutes across southeast Denver. In Denver…some underpasses were flooded with several feet of water which stranded motorists. As a result…the fire department conducted at least 10 water rescues. Some basements were inundated with up to 4 feet of water which caused extensive flood damage. The Platte Valley and Western Model Railroad Club`s model train display in Union Station was also damaged when 3 to 4 inches of mud and water spilled over some of the command and control systems. Several display modules and scenery pieces in a storage room were also damaged. The entire display spanned more than one thousand feet of track in a room that was once used as the jail at union station in the 1900s. Urban and small stream flooding was reported across the surrounding Denver suburbs. The storm left about 28000 Xcel customers without power when the storm snapped trees and power lines. In addition…heavy rain produced flash flooding in the four mile canyon burn scar. Four debris slides occurred along four mile canyon drive…including one that was 100 yards wide and 4 feet deep. Several rockslides were reported in Lefthand and Boulder canyons. At Denver International Airport…1.04 inches of rain was observed. A peak wind gust of 46 mph from the southeast was also observed.
In 2012…heavy rain produced flash flooding in Boulder County near Jamestown. James Canyon Drive was closed after heavy rain washed out a section of the roadway. Heavy rain washed out a section of Magnolia Road…east-southeast of Nederland. Nearby…a trained spotter 4 miles east-northeast of Nederland… Measured 2.20 inches of rainfall. Flash flooding was also reported in the Fourmile burn area along Summerville Road. In Dacono…in southern Weld County… The Colorado Department of Transportation used snowplows to clear standing water…up to 6 inches deep…from a section of Interstate 25. The interstate was closed in both directions for nearly two hours. South of the Denver…in central Douglas County… Flash flooding was reported near Perry Park…where 2.5 inches of rain fell in one hour.
In 2014…an Arvada resident was injured by a nearby lightning strike while he recorded a video of a thunderstorm with his cell phone. He was standing in his garage…when a nearby lightning bolt knocked him out. He suffered overall body aches and had a ringing sensation in one of his ears. In Denver… Lightning caused a power outage that affected the RTD light rail lines for a short time. In Castle Pines…lightning sparked a small attic fire. Severe thunderstorms produced large hail…from quarter to golfball size… And damaging winds across Arapahoe…Boulder and Jefferson counties including: northwest Arvada…Littleton and Louisville. Flash flooding was reported near Evergreen in central Jefferson County. Heavy rain…up to 2 inches in one hour… Flooded several residences and washed out several bridges along forest estate road. Heavy rainfall also produced street flooding in Denver along with some basement flooding. The strong winds…estimated to 60 mph… Downed trees and power lines in southwest Littleton. At Denver International Airport…0.15 inches of rainfall was observed along with a peak wind gust to 42 mph from the southeast.
Continue reading July 5 to July 11: This week in Denver weather history →