WFO Denver/Boulder

...July 31 in Metro Denver weather history...
13-5 In 2008, a streak of 24 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. 18-2 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. 27-31 In 1956, 96 percent of the total precipitation for the month of July occurred over the last five days of the month. Heavy thunderstorms produced 4.00 inches of rainfall at Stapleton Airport. This amount of precipitation in 5 days or less had been exceeded only 3 times in previous record. The last time had been in December of 1913 as snow. Considerable property damage occurred across metro Denver from flooding. 31 In 1873, the all-time lowest recorded temperature in July, 42 degrees, occurred. The same temperature also occurred on July 4, 1903. In 1874, during the late afternoon rain and hail fell for 5 minutes followed by brief heavy rain. Pieces of solid ice of irregular shape fell upon the roof of the station. The hail stones measured 1 1/2 inches in diameter. Precipitation (rain and melted hail) was only 0.16 inch. In 1889, the high temperature climbed to 100 degrees in downtown Denver. In 1919, heavy thunderstorm rainfall totaled 2.59 inches in downtown Denver during the evening. Rainfall was 1.90 inches in an hour, a new record at that time. In 1961, over an inch of rain in a short period of time caused flooding of streets and basements in Denver. Rainfall totaled 1.30 inches at 11th and Lincoln in central Denver. In 1964, the temperature reached 91 degrees in Denver, making this the 27th day of the month that the temperature reached 90 degrees or more. This is the all time record for 90 degree days in a month in Denver. In 1972, one inch diameter hail fell in Hudson northeast of Denver. In 1976, during the evening hours extremely heavy thunderstorm rains produced flash flooding in Big Thompson Canyon which killed 144 people between Estes Park and Loveland. No significant weather occurred in metro Denver at the time. In 1987, 1 inch diameter hail fell in Lakewood and 3/4 inch hail fell near Louisville. Southeast Boulder County was drenched with 1.25 inches of rain in just 20 minutes. In 1993, thunderstorm winds damaged a chimney of a home near Parker. In 1996, a weak tornado (F0) was sighted 12 miles east of Denver International Airport. No damage was reported. In 1998, heavy monsoonal thunderstorm rain triggered a mud slide in Blackhawk. The mudslide blocked Main St. and caused an estimated half million dollars in damage to a casino. Heavy thunderstorm rain, up to 3 inches in an hour, caused a flash flood along Buffalo Creek. Portions of County Road 126 just south of the town of Buffalo Creek were washed out. The flood waters nearly washed away the bridge as mud and debris slammed into the structure. Hail to 1 3/4 inches in diameter fell near Idaho Springs. In 2004, severe thunderstorm winds toppled a 65-foot blue spruce tree in Parker. The tree landed on a home damaging the roof and gutters. The downed tree poked dozens of holes into the shingles.

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