Flagstaff
September
Weather in Flagstaff for September 2025
Your guide to Flagstaff weather in September - trends and predictions
In general, the average temperature in Flagstaff at the beginning of September is 26.6 °F. As the month progressed, temperatures tended to moderately fall, reaching an average of 25.3 °F by the end of September.
With an average of 4 rainy days, Flagstaff experiences minimal rainfall in September.
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Temperatures
Rain 🌧️
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26
Dry days
4
Rainy days
0
Snow days
23°/14°
Temperatures
20 km/h
Avg max wind
37 %
Avg humidity
Flagstaff in September average weather
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| Mon. | Tue. | Wed. | Thu. | Fri. | Sat. | Sun. |
|---|---|---|---|---|---|---|
| 1  25° | 2 26° | 3  27° | 4 27° | 5 28° | 6 28° | 7  25° |
| 8  24° | 9  24° | 10 26° | 11  25° | 12 23° | 13 23° | 14 23° |
| 15 22° | 16  20° | 17 16° | 18 18° | 19 20° | 20 19° | 21 15° |
| 22 20° | 23 22° | 24 24° | 25 25° | 26 25° | 27 26° | 28 28° |
| 29 25° | 30 24° |
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Temperatures trend during September in Flagstaff
See the weather trend as well as the moving average line
September weather day by day
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| Date | Weather | Temperatures | Rain | UV | More |
|---|---|---|---|---|---|
| Sept. 1 | Sunny | 25° /14° | 0 mm | 7 | |
| Sept. 2 | Sunny | 26° /15° | 0 mm | 7 | |
| Sept. 3 | Partly cloudy | 27° /15° | 0 mm | 7 | |
| Sept. 4 | Partly cloudy | 27° /16° | 0 mm | 7 | |
| Sept. 5 | Sunny | 28° /17° | 0 mm | 7 | |
| Sept. 6 | Sunny | 28° /15° | 0 mm | 7 | |
| Sept. 7 | Patchy light rain | 25° /15° | 3.4 mm | 6 | |
| Sept. 8 | Patchy light rain with thunder | 24° /14° | 2.2 mm | 5 | |
| Sept. 9 | Thundery outbreaks possible | 24° /14° | 0.6 mm | 5 | |
| Sept. 10 | Partly cloudy | 26° /14° | 0 mm | 7 | |
| Sept. 11 | Cloudy | 25° /16° | 0 mm | 6 | |
| Sept. 12 | Sunny | 23° /13° | 0 mm | 6 | |
| Sept. 13 | Sunny | 23° /10° | 0 mm | 6 | |
| Sept. 14 | Sunny | 23° /12° | 0 mm | 6 | |
| Sept. 15 | Sunny | 22° /12° | 1.7 mm | 6 | |
| Sept. 16 | Patchy rain possible | 20° /11° | 0 mm | 5 | |
| Sept. 17 | Partly cloudy | 16° /8° | 0 mm | 5 | |
| Sept. 18 | Partly cloudy | 18° /8° | 0 mm | 5 | |
| Sept. 19 | Sunny | 20° /10° | 0 mm | 6 | |
| Sept. 20 | Sunny | 19° /11° | 0 mm | 5 | |
| Sept. 21 | Thundery outbreaks possible | 15° /9° | 0 mm | 4 | |
| Sept. 22 | Cloudy | 20° /11° | 0 mm | 5 | |
| Sept. 23 | Cloudy | 22° /13° | 0 mm | 5 | |
| Sept. 24 | Sunny | 24° /14° | 0 mm | 6 | |
| Sept. 25 | Sunny | 25° /15° | 0 mm | 7 | |
| Sept. 26 | Partly cloudy | 25° /17° | 0 mm | 7 | |
| Sept. 27 | Partly cloudy | 26° /18° | 0 mm | 7 | |
| Sept. 28 | Partly cloudy | 28° /18° | 0 mm | 7 | |
| Sept. 29 | Cloudy | 25° /19° | 0 mm | 6 | |
| Sept. 30 | Cloudy | 24° /19° | 0 mm | 5 | |
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Important Notice
Our weather forecast for Flagstaff 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 Flagstaff forecast closer to your planned date for the most up-to-date weather information.
Flagstaff in September - FAQ
What are the expected maximum and minimum temperatures in Flagstaff during September?
Enjoy moderate daytime temperatures of up to 23° and cooler nights around 14°. Ideal for a range of outdoor activities, from hiking to city tours.
How much rainfall should be expected in Flagstaff during September?
Rainfall in Flagstaff during September is rare to nonexistent, with the total expected rainfall being less than 10 mm and approximately 4 days seeing any precipitation. Planning without the concern for rain is generally straightforward during this very dry period.
What are the typical wind conditions in Flagstaff during September?
The average wind speed in Flagstaff during September is 20 km/h, suggesting breezy to windy conditions, depending on your activities.
September rainfall patterns in Flagstaff
Explore the daily rainfall trends and prepare for Flagstaffs September weather 💧
UV exposure in Flagstaff during September
Stay informed about UV levels for safe outdoor activities throughout the month of September ☀️
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