September 2026 will be remembered as the month that put an exclamation point on an extraordinary water year of heat and dryness in Boulder, with less than 20% of normal precipitation falling during the month and temperatures more than five degrees above average. Despite a strong late-season monsoon, moisture largely avoided the Front Range, and especially Boulder County, culminating with a great modeling collapse of a significant rain event in the final days of the month tied to the remnants of Hurricane Polo.
Here’s a graphical look at how September 2026 unfolded across Boulder, Denver, and the Front Range — and how it compared to climatology.
September 2026 Temperatures:
September 2026 Precipitation:
Precipitation totals during September 2026 across the Boulder-Denver Metro area
How does September 2026 fit into the last 76 years?
How does September 2026 fit into the last 12 months?
Drought Update
Colorado remains deeply entrenched in drought, though frequent rains this summer to the east have resolved the drought for some counties east of Denver.
Finally the monsoon delivered! For once more of the state saw drought improvement in a month than worsening. Southern and southeast Colorado saw the most improvement. Eastern Boulder County and Broomfield unsurprisingly got worse.
Our top posts of September 2026
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