Fort Collins (CO)
September
Weather in Fort Collins, Colorado for September 2025
Your guide to Fort Collins weather in September - trends and predictions
In general, the average temperature in Fort Collins at the beginning of September is 29.3 °F. As the month progressed, temperatures tended to moderately fall, reaching an average of 27.3 °F by the end of September.
Fort Collins experiences moderate rainfall in September, with an average of 7 rainy days and a total precipitation of 60 mm.
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Temperatures
Rain 🌧️
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23
Dry days
7
Rainy days
0
Snow days
26°/12°
Temperatures
19 km/h
Avg max wind
37 %
Avg humidity
Fort Collins Weather September
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Temperatures trend during September in Fort Collins
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September weather in Fort Collins day by day
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| Date | Weather | Temperatures | Rain | UV | More |
|---|---|---|---|---|---|
| Sept. 1 |  Thundery outbreaks possible | 31° /14° | 0.1 mm | 8 | |
| Sept. 2 |  Overcast | 31° /15° | 0.3 mm | 7 | |
| Sept. 3 |  Patchy light drizzle | 32° /17° | 2.7 mm | 7 | |
| Sept. 4 |  Partly cloudy | 28° /14° | 2.8 mm | 7 | |
| Sept. 5 | Partly cloudy | 24° /12° | 0.3 mm | 6 | |
| Sept. 6 |  Sunny | 29° /11° | 0 mm | 7 | |
| Sept. 7 | Sunny | 30° /13° | 0.2 mm | 7 | |
| Sept. 8 | Sunny | 30° /14° | 0 mm | 8 | |
| Sept. 9 |  Cloudy | 30° /14° | 1.2 mm | 7 | |
| Sept. 10 |  Patchy rain possible | 25° /13° | 3 mm | 6 | |
| Sept. 11 |  Fog | 24° /12° | 1.8 mm | 6 | |
| Sept. 12 | Sunny | 27° /10° | 0 mm | 7 | |
| Sept. 13 | Cloudy | 26° /11° | 0 mm | 7 | |
| Sept. 14 | Overcast | 24° /11° | 0 mm | 6 | |
| Sept. 15 | Partly cloudy | 24° /11° | 0 mm | 6 | |
| Sept. 16 | Sunny | 26° /10° | 0.6 mm | 6 | |
| Sept. 17 | Partly cloudy | 25° /11° | 0 mm | 6 | |
| Sept. 18 | Thundery outbreaks possible | 27° /9° | 0.1 mm | 6 | |
| Sept. 19 | Thundery outbreaks possible | 24° /11° | 0 mm | 6 | |
| Sept. 20 | Patchy light drizzle | 27° /10° | 0.2 mm | 7 | |
| Sept. 21 | Patchy rain possible | 21° /9° | 6.7 mm | 5 | |
| Sept. 22 | Partly cloudy | 17° /7° | 39.6 mm | 5 | |
| Sept. 23 | Sunny | 24° /7° | 0 mm | 6 | |
| Sept. 24 | Sunny | 23° /8° | 0 mm | 6 | |
| Sept. 25 | Sunny | 27° /10° | 0 mm | 7 | |
| Sept. 26 | Sunny | 29° /12° | 0 mm | 8 | |
| Sept. 27 | Sunny | 29° /15° | 0 mm | 7 | |
| Sept. 28 | Sunny | 29° /12° | 0 mm | 7 | |
| Sept. 29 | Sunny | 29° /11° | 0 mm | 8 | |
| Sept. 30 | Patchy light drizzle | 25° /10° | 0.4 mm | 6 | |
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Important Notice
Our weather forecast for Fort Collins in September is based on the analysis of historical data rather than real-time forecast models. While this provides a general overview, weather conditions can change. We recommend that you check the Fort Collins forecast closer to your planned date for the most up-to-date weather information.
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Fort Collins in September - FAQ
What are the expected maximum and minimum temperatures in Fort Collins during September?
Enjoy moderate daytime temperatures of up to 26° and cooler nights around 12°. Ideal for a range of outdoor activities, from hiking to city tours.
How much rainfall should be expected in Fort Collins during September?
Moderate rainfall is anticipated in Fort Collins during September, with a total of 60 mm spread over approximately 7 days. Considering plans for rainy days is advisable.
What are the typical wind conditions in Fort Collins during September?
The average wind speed in Fort Collins during September is 19 km/h, suggesting breezy to windy conditions, depending on your activities.
September rainfall patterns in Fort Collins
Explore the daily rainfall trends and prepare for Fort Collinss September weather 💧
UV exposure in Fort Collins during September
Stay informed about UV levels for safe outdoor activities throughout the month of September ☀️
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