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Public Information Statement
National Weather Service Denver/Boulder CO
259 AM MDT TUE SEP 8 2026

...Today in metro Denver weather history...

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.
5-8   In 2020...a strong upper level low brought an end to record
        heat to the Front Range urban corridor...and provided Denver
        its second earliest measurable snowfall on record. Numerous
        heat records were set leading up to the snowfall...and
        several new snowfall and cold records were also broken in
        this abrupt bout with winter.  Denver set its all time
        record high for September...reaching 101 degrees during the
        afternoon. This was also the latest date a 100 degree
        reading has ever been observed in Denver.  Another daily
        record high was then tied on September 6th when Denver hit
        97 degrees. September 7th was the last day of heat when
        Denver`s high temperature reached 93 degrees.  That tied
        Denver for the record for the number of 90 degree days for
        a year at 73...and was also the warmest temperature ever
        recorded before a day of measurable snowfall.  By the
        evening of September 7th...a series of cold fronts
        progressed southward from Wyoming into Colorado...
        dropping the temperature into the low 30s by the early
        morning hours of September 8th.  Snow developed across
        the Front Range mountains and foothills overnight...
        while a mix of rain and snow developed along the I-25
        corridor.  A few locations picked up light snowfall
        accumulations in the morning. Accumulating snow was
        mostly confined to the higher elevations much of the
        day...before spreading across the plains during the
        late afternoon and evening. Storm totals ranged from
        4 to 10 inches in the mountains...with 3 to 6 inches
        near the foothills.  A total of 5.6 inches of snow
        was measured at the NWS Boulder office...while at
        Denver International Airport...the official
        measurement was 1.0 inch.
5-9   In 1988...layers of smoke aloft from large forest fires in
        Yellowstone National Park completely obliterated the sun
        at times.  At Stapleton International Airport...surface
        visibility was reduced at times to 5 and 6 miles in smoke.
5-13  In 2010...the Fourmile Canyon Wildfire...northwest of Boulder...
        broke out on the morning of the 5th.  It originated from
        an unattended fire pit at a local residence. The wildfire
        quickly consumed 5 1/2 square miles or 3500 acres the
        first day...and forced the evacuation of over three
        thousand residents.  Erratic 45-mph gusts sent the fire in
        two directions at times. Very dry weather conditions
        preceded the fire. The combination of strong winds...low
        relative humidities and dry fuels allowed the wildfire
        spread rapidly through the steep...heavily forested terrain.
        The flames were reportedly 20 to 50 feet in length.  Towns
        within the burn area included Salina...Wallstreet and Gold
        Hill. The dry conditions coupled with gusty winds ranging
        from 45 to 64 mph persisted for several more days. Fire
        managers used as many as 700 firefighters and support
        personnel from 35 agencies and seven air tankers to battle
        the wildfire.  A total of 6181 square acres or
        approximately 10 square miles were burned.  The Fourmile
        Canyon Wildfire was the most destructive fire in Colorado
        history in terms of the damage to personal property.  It
        destroyed 171 homes with an estimated cost of 217 million
        dollars.
7-8   In 1884...a windstorm from mid-afternoon until the early
        morning hours of the 8th produced south winds sustained
        to 48 mph.  The strong winds toppled several trees in
        the city.
      In 1892...there was a trace of rainfall each day.  This
        together with a trace of rain on both the 2nd and 3rd was
        the only rainfall of the month...making the month the driest
        on record.  The record was equaled in 1944.
8     In 1886...the last thunderstorm of the season pelted the
        city with hail the size of beans and dropped 0.81 inch of
        precipitation.
      In 1962...the earliest first freeze of the season occurred.
        The temperature dipped to a low of 31 degrees.
      In 1973...hail up to 1 1/2 inches in diameter fell northeast
        of Boulder.  A tornado was reported by a pilot east of
        Parker.  No damage was reported.

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