September 2025 Monthly Weather Summary

Описание: September 2025 Monthly Weather Summary

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For a written September 2025 weather summary, please visit our website at https://www.weather.gov/media/gjt/Sep...
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The month of September started out under high pressure, with warm temperatures and abundant sunshine. Moisture very slowly began to infiltrate from the south, bringing returning chances of mountain showers as the week wore on, eventually overspreading all of eastern Utah and western Colorado by the end of the week. These storms produced heavy rain and frequent lightning, and temperatures cooled to near-normal values. The second week of the month saw a very similar pattern, with dry and warm conditions to start, and wet and cool for the end. However, severe weather made a return at the end of this week, with widespread severe thunderstorms producing large hail, flash flooding, and even two tornadoes. The tornadoes occurred in Southeast Utah on the afternoon of the 13th, and while one was left unrated, the other was found to have been an EF2. After all that excitement, the middle of the month saw a return to quieter and seasonable conditions, although high terrain showers and storms lingered, occasionally becoming widespread and bringing some precipitation to the lower elevations. By the last week of the month, the pattern had shifted away from the more monsoonal type we'd seen and toward a more fall-like pattern of passing upper level waves driving precipitation. Passing waves during the last week of the month brought cooler temperatures and periods of scattered to widespread showers and thunderstorms. This pattern continued through the end of the month, with near-normal and quiet days punctuating cooler and wetter weather.

The month of September was generally warmer than normal, with nine of the ten automated weather observation stations located at airports across eastern Utah and western Colorado finishing the month with above normal mean temperatures. The only station to have a below normal mean temperature was Aspen-Pitkin County Airport. Mean temperature departures ranged from 0.7F below normal to 1.5F above normal. The warmest temperature recorded at any of the ten sites was 95F, at Canyonlands Airport, near Moab, UT, on the 2nd. The coldest temperature recorded was 31F, which occurred at Aspen-Pitkin County Airport on the 24th. The month was also generally drier than normal, with nine of the ten automated weather observation stations recorded below normal total precipitation. Total precipitation departures ranged from 1.03 inches above normal to 0.88 inches below normal. The most precipitation fell at Meeker Airport, where the month-end total of 2.71 inches was 1.03 inches above normal. The least precipitation fell at Vernal Airport, where the month-end total of 0.34 inches was 0.88 inches below normal. At Canyonlands Airport, near Moab, UT, the month-end total of 0.89 inches was exactly normal for September.

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Please note that all data mentioned is collected from our automated observing stations from 10 different airports across eastern Utah and western Colorado. Some of our cooperative observers in more remote areas may have measured warmer or colder temperatures, or more or less precipitation than what was mentioned in this summary.


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National Weather Service
Weather Forecast Office
Grand Junction, CO