Fort Collins (CO)
September
Weather in Fort Collins, Colorado for September 2026
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 28.4 °C. As the month progressed, temperatures tended to noticeably cool down, reaching an average of 25.9 °C by the end of September.
Fort Collins experiences moderate rainfall in September, with an average of 7 rainy days and a total precipitation of 45.4 mm.
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Temperatures
Rain 🌧️
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23
Dry days
7
Rainy days
0
Snow days
25°/12°
Temperatures
19 km/h
Avg max wind
41 %
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 |  Sunny | 30° /14° | 0 mm | 7 | |
| Sept. 2 |  Overcast | 30° /14° | 0.2 mm | 7 | |
| Sept. 3 |  Patchy light drizzle | 31° /15° | 1.8 mm | 7 | |
| Sept. 4 |  Partly cloudy | 29° /13° | 1.9 mm | 7 | |
| Sept. 5 | Partly cloudy | 23° /11° | 0.2 mm | 6 | |
| Sept. 6 | Sunny | 27° /10° | 0 mm | 7 | |
| Sept. 7 | Sunny | 29° /13° | 0.1 mm | 7 | |
| Sept. 8 | Sunny | 30° /14° | 0 mm | 7 | |
| Sept. 9 |  Cloudy | 29° /14° | 0.8 mm | 6 | |
| Sept. 10 | Partly cloudy | 26° /12° | 2 mm | 6 | |
| Sept. 11 |  Fog | 25° /13° | 1.2 mm | 6 | |
| Sept. 12 | Sunny | 26° /11° | 0 mm | 6 | |
| Sept. 13 | Cloudy | 25° /11° | 0 mm | 6 | |
| Sept. 14 | Overcast | 24° /11° | 0 mm | 5 | |
| Sept. 15 | Partly cloudy | 25° /11° | 0 mm | 6 | |
| Sept. 16 | Sunny | 25° /10° | 0.4 mm | 6 | |
| Sept. 17 | Partly cloudy | 23° /11° | 0 mm | 5 | |
| Sept. 18 | Overcast | 24° /9° | 0 mm | 5 | |
| Sept. 19 |  Thundery outbreaks possible | 24° /10° | 0 mm | 6 | |
| Sept. 20 | Patchy light drizzle | 26° /10° | 0.1 mm | 6 | |
| Sept. 21 |  Patchy rain possible | 22° /10° | 4.5 mm | 5 | |
| Sept. 22 | Partly cloudy | 19° /8° | 27.3 mm | 5 | |
| Sept. 23 | Overcast | 21° /7° | 4.5 mm | 5 | |
| Sept. 24 | Partly cloudy | 21° /8° | 0 mm | 6 | |
| Sept. 25 | Sunny | 26° /9° | 0 mm | 7 | |
| Sept. 26 | Partly cloudy | 29° /11° | 0 mm | 7 | |
| Sept. 27 | Sunny | 26° /13° | 0 mm | 6 | |
| Sept. 28 | Sunny | 27° /12° | 0 mm | 6 | |
| Sept. 29 | Sunny | 27° /12° | 0 mm | 7 | |
| Sept. 30 | Patchy light drizzle | 25° /9° | 0.3 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.
Change Month
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 25° 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?
In September, Fort Collins can expect light to moderate rainfall, totaling 45.4 mm across approximately 7 days. Occasional showers are possible, and planning ahead for them could be helpful.
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 💧
Typically, Fort Collins has 7 rainy days in September with a total of 45.4 mm of rainfall.
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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