This time of year we usually see calm conditions as we begin the transition to fall.  However, that is not always the case as is seen in our look back at this week in history. Everything from thunderstorms with hail to tornadoes can and have been experienced.

From the National Weather Service:

19-30

In 1875…grasshoppers appeared in great numbers at 10:00 am on the 19th. Thousands landed on the ground. The streets were literally covered with them. Swarms of grasshoppers were seen on each day. All gardens in the city were devastated…and in the countryside the grasshoppers were very destructive to ripened grain. On the 30th the grasshoppers were so numerous as to almost darken the sun.

26-27

In 1980…two heavy thunderstorms hit Arvada and Westminster… Dumping up to 1.50 inches of rain in less than an hour. At least two streets were washed out and a number of homes and cars were damaged when a creek flooded. Three homes in Arvada sustained minor lightning damage.

27

In 1910…a thunderstorm produced south winds sustained to 40 mph.

In 1961…strong thunderstorm winds and heavy rain occurred at 79th and Federal Blvd. in Westminster. The strong winds blew the roofs off lumber sheds onto parked cars.

In 1967…a young woman was killed by lightning while horseback riding in the suburbs just west of Denver. Her horse died several hours after the incident. A young man and another young woman were also knocked from their horses by the impact of the lightning and required hospitalization.

In 1991…heavy thunderstorm rainfall totaled 0.91 inch at Stapleton International Airport…where 1/4 inch diameter hail was measured.

In 1996…localized street flooding occurred in the Fort Lupton area when 2 to 3 inches of rain fell in 45 minutes. The roof of a community college began leaking…which caused damage to ceiling tiles. The roof was under repair from hail damage which had occurred earlier in the summer. A weak tornado (F0) was sighted near Fort Lupton. No damage was reported.

In 1999…a slow moving thunderstorm dumped 5 inches of rain in 2 hours near Dacono. A severe thunderstorm produced 3/4 inch diameter hail in Castle Rock.

In 2002…severe thunderstorms spread large hail over metro Denver. Hail as large as 2 inches in diameter fell in Jefferson County 5 to 11 miles northwest of Golden. Other large hail reports included: 1 1/2 inches near Golden and in Lakewood; 1 1/4 inches in Nederland; 1 inch hail near Elizabeth…Louviers…Rollinsville…and Blackhawk; 7/8 inch hail near Acequia in Douglas County. A thunderstorm produced a trace of rain and a microburst wind gust to 52 mph at Denver International Airport.

In 2003…lightning struck a house and sparked a fire in Arvada. Damage to the roof and ceiling was extensive.

In 2005…lightning struck an unoccupied home in Parker. The resulting fire damaged the roof…attic…and second floor bedroom. Damage was estimated at 15 thousand dollars.

27-28

In 2004…a brief chilly spell resulted in three temperature records. The high temperature of 55 degrees on the 27th was a record low maximum for the date. The low temperature of 48 degrees on the 27th equaled the record minimum for the date. The low temperature of 42 degrees on the 28th was a record minimum for the date.

28

In 1887…a dry thunderstorm produced north winds to 48 mph but only a trace of rainfall.

In 1968…one man was seriously injured by lightning while riding on a roller coaster at a Denver amusement park. An airline employee was injured when lightning struck a jetliner he was servicing at Stapleton International Airport. A lightning-caused fire did extensive damage to one house and minor damage to several others in the city of Denver.

In 1970…a microburst wind gust to 53 mph was recorded at Stapleton International Airport.

In 2002…a severe thunderstorm produced 3/4 inch diameter hail near Parker.

In 2005…lightning sparked a small fire near Jamestown. The blaze was quickly contained and consumed less than an acre.

29

In 1876…after the passage of a gentle rain shower to the east during the late evening hours…the moon shone brightly and a remarkably bright lunar rainbow appeared.

In 1910…an apparent cold front produced sustained northeast winds to 40 mph.

In 1946…the high temperature warmed to only 55 degrees…the record low maximum for the month.

In 1989…a spectacular lightning display knocked out power to 300 blocks in southeast Denver. One bolt started a fire in a lumber yard in the northeast part of the city…and the attic of a home in the same area was set ablaze by a lightning bolt.

In 1996…3/4 inch diameter hail was measured in Parker.

In 2000…lightning struck two homes in Thornton. The extent of damage was unknown.

In 2002…two small tornadoes caused damage in southeast metro Denver. The first tornado…associated with a multi-vortex storm…touched down briefly near E-470 and South Jordan Road. Some fences were damaged…and a few trees were blown down. A few of the homes also sustained minor roof damage. Damage from this storm totaled 100 thousand dollars. The second tornado associated with the storm touched down in a subdivision that was under construction at Gartrell and Arapahoe roads. Four large condominiums under construction were destroyed. The most heavily damaged portions of the structures were still in the framing stages. Adjacent sections where enclosed walls were in place were not destroyed. A man suffered 4 broken ribs and several cuts and bruises when the trailer he sought shelter in was flipped three times and torn apart by the twister. Damage from this storm totaled 6 million dollars. A severe thunderstorm produced 1 inch diameter hail near Evergreen.

In 2006…severe thunderstorms produced large hail in the foothills west of Denver. Hail to 1 inch in diameter fell near Blackhawk. Hail as large as 7/8 inch was measured near Idaho Springs…along with 3/4 inch hail near Nederland and conifer.

30

In 1981…60 mph winds were reported in Boulder.

In 2004…a severe thunderstorm produced hail as large as 1 inch in diameter in south Aurora near Cherry Creek.

In 2016…an intense thunderstorm produced very heavy rain and hail in Westminster…where radar estimated up to 3.6 inches of rainfall. Several vehicles were stranded in 2 to 3 feet of moving water at the intersection of 72nd Ave. and Pecos St. Street flooding was also reported on U.S. 36 at Pecos St.

31

In 1951…hail as large as 1 3/4 inches in diameter caused an estimated 300 thousand dollars damage in metro Denver. Hail as large as 1 1/2 inches in diameter was measured at Stapleton Airport.

In 1978…strong thunderstorm winds tore the roof off an apartment building in Aurora…downed trees…and damaged windows in Denver. A microburst wind gust to 58 mph was recorded at Stapleton International Airport.

In 1985…a thunderstorm wind gust to 60 mph was clocked at Buckley Field in Aurora.

In 1997…hail to 1 1/4 inches in diameter was measured in Aurora.

In 2006…a female postal worker was struck and injured by lightning while delivering mail in Westminster.

In 2008…lightning struck a home in Brighton…damaging the roof and a bedroom. The damaged totaled 20 thousand dollars.

In 2020…a worsening drought that started in the spring of 2020…continued through August. The month of August tied with 2011 for the warmest August on record. It also occurred in the middle of the second warmest summer on record. The combination of hot and dry conditions…in addition to critically dry fuels from years of beetle kill…resulted massive wildfires. The Cameron Peak fire…which became the largest wildfire in the state`s history started on August 13th and continued to burn into October. Smoke from this wildfire in addition to several other large wildfires in Colorado and the West resulted in multiple days of extremely poor air quality. In addition…the air quality in Denver and the entire Front Range had deteriorated severely due to the very warm temperatures and high ozone content… which had spiked significantly. In August…26 days in the month equaled or exceeded 90 degrees.

1

In 1951…large hail pounded Boulder…causing thousands of dollars in damage to roofs and automobiles. Heavy thunderstorm rainfall flooded basements and produced widespread street flooding.

In 1966…severe thunderstorms caused local flooding in areas from Denver to the north and east. There was scattered damage from hail and lightning. Streets were flooded in Boulder…and streets and basements were flooded in several areas of metro Denver. The public reported 1 inch diameter hail in Aurora and near Cheery Creek Reservoir. Thunderstorm rainfall totaled only 0.39 inch at Stapleton International Airport.

In 1985…severe thunderstorms dumped heavy rain and hail at many locations along the Front Range from Denver south. The southern and eastern suburbs of metro Denver were especially hard hit. Rainfall from 1 1/2 to 3 inches caused extensive street flooding in Aurora where two creeks rose out of their banks. Two homes in the city suffered minor lightning damage. Almost 4 inches of rain fell in the Parker area. Hail up to ping-pong ball size piled up to a foot deep and closed a road in Evergreen. Hail as large as 1 3/4 inches in diameter was reported 8 miles northeast of Deckers. Wind gusts to 65 mph were estimated in southeast Aurora.

In 1990…marble size hail piled up to 2 inches deep in the foothills community of Kittredge…18 miles southwest of Denver. As much as half an inch of rain fell in just 15 minutes and caused minor road and small stream flooding. A thunderstorm dropped pea to marble size hail and brief heavy rain near Ward road and 64th avenue in Arvada. Minor street and small stream flooding was reported in the area.

In 1995…a strong thunderstorm microburst with only a few drops of rain produced a recorded wind gust to 85 mph at the site of the former Stapleton International Airport. The wind gust occurred at 8:30 pm MDT. The all-time highest recorded temperature in September…97 degrees… Occurred. The same temperature also occurred on September 5…1899…September 4…1960…and September 4… 1995.

In 2019…the high temperature in Denver reached 98 degrees… which not only broke the record for the date…but also set a new monthly record for the month of September.

1-5

In 1995…record breaking heat occurred on the first 5 days of the month when the temperature climbed into the 90’s on each day. Record high temperatures of 97 degrees on both the 1st and 4th equaled the all-time record maximum for the month. High temperature of 95 degrees on the 3rd was a record for the date. High temperatures of 94 degrees on both the 2nd and the 5th were not records. The low temperature of 64 degrees on the 4th equaled the record high minimum for the date.

1-7

In 1978…the temperature reached 90 degrees or more on seven consecutive days with the highest temperature…94 degrees… Recorded on both the 4th and 6th.

1-30

In 2020…a worsening drought that started in the spring and continued through September. Outside of an early season snow on the 8th…the month of September was another unseasonably warm and dry period. The combination of hot…mostly dry conditions…and critically dry fuels… resulted in a continuation and rapid expansion of several massive wildfires. The Cameron Peak fire…which became the largest in the state`s history started on August 13th…and continued through September. As a result…very poor air quality continued to impact Denver and the entire Front Range. Denver recorded the most days ever with a high temperature of 90 degrees or better; 75 days. The last of which was 91 degrees on the 24th. The previous record was 73 days set in 2012.

2

In 1938…heavy cloudbursts in the foothills near the top of Genesee mountain caused flash flooding on bear creek at Morrison. Nearly 8 inches of rain fell just north of Morrison in 6 hours and drowned 6 people in a car between Morrison and Kittredge. Damage was estimated at nearly a half million dollars. Flash flooding also occurred on south Boulder creek in Eldorado Springs. Rainfall totaled 4.42 inches in Eldorado Springs…and rainfall was estimated to more than 6 inches in the foothills west of the town. Many buildings and residences were damaged in Eldorado Springs…and bridges were swept away. The high waters forced residents from their homes as far downstream as Erie. This was the flood of record on south Boulder creek.

In 1973…hail to 3/4 inch diameter was reported in Boulder.

In 1987…lightning struck two men who were standing under a tree in downtown Denver. Both were seriously injured and hospitalized.

In 1996…lightning sparked a brush fire in the south buffer zone of the Rocky Flats Environmental Test Facility. No structures were damaged…but the fire burned about 100 acres of grassland before being contained.

In 2019…the record high temperature of 100 degrees was set in Denver…shattering the previous daily record of 95 established in 1983. Not only was the daily record set… it also set the all time monthly record for September. The previous record for the month was 98 degrees…which was set the previous day. In addition…it was the latest 100+ degree day ever reached during the calendar year in Denver`s climate record…breaking the previous mark by 17 days. The previous record occurred on August 16th…2002. Lastly…it was the hottest Labor Day on record.

2-3

In 1892…there was a trace of rainfall each day. This… Together with a trace of rain on both the 7th and 8th…was the only rainfall of the month…making the month the driest on record. The monthly record was equaled in 1944.