Weather in Fairfax, Virginia for September 2025
Until now, September 2025 in Fairfax has been nearly identical to the historical average, with a temperature of 26.4 °F (showing only a slight deviation of 0.3 °F).
The forecast for the next days in Fairfax predicts temperatures to be around 25 °F, close to the historical average.
In general, the average temperature in Fairfax at the beginning of September is 26 °F. As the month progressed, temperatures tended to moderately fall, reaching an average of 24.3 °F by the end of September.
The climate of Fairfax in September is notably wet, with an average of 11 rainy days, and a total of 215.8 mm of precipitation.
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Fairfax Weather September
Temperatures trend during September in Fairfax
September weather in Fairfax day by day
| Date | Weather | Temperatures | Rain | UV | More |
|---|---|---|---|---|---|
| Sept. 1 |  Patchy light drizzle | 27° /18° | 0.7 mm | 6 | |
| Sept. 2 |  Partly cloudy | 24° /18° | 0 mm | 6 | |
| Sept. 3 |  Sunny | 24° /15° | 0 mm | 6 | |
| Sept. 4 |  Overcast | 28° /16° | 3.4 mm | 7 | |
| Sept. 5 | Partly cloudy | 29° /17° | 1.6 mm | 7 | |
| Sept. 6 |  Patchy rain possible | 29° /19° | 36.4 mm | 7 | |
| Sept. 7 | Patchy rain possible | 21° /16° | 3.5 mm | 5 | |
| Sept. 8 | Sunny | 24° /12° | 0 mm | 7 | |
| Sept. 9 | Sunny | 24° /13° | 0 mm | 7 | |
| Sept. 10 | Sunny | 26° /15° | 0 mm | 6 | |
| Sept. 11 | Sunny | 27° /16° | 0 mm | 7 | |
| Sept. 12 | Sunny | 28° /17° | 0 mm | 7 | |
| Sept. 13 | Partly cloudy | 28° /17° | 0 mm | 7 | |
| Sept. 14 |  Mist | 29° /19° | 0 mm | 6 | |
| Sept. 15 | Partly cloudy | 27° /17° | 0 mm | 1 | |
| Sept. 16 | Patchy rain possible | 19° /18° | 0.1 mm | 0.5 | |
| Sept. 17 |  Heavy rain | 17° /15° | 31.9 mm | 0.2 | |
| Sept. 18 | Partly cloudy | 29° /18° | 0 mm | 1.4 | |
| Sept. 19 | Sunny | 33° /18° | 0 mm | 0 | |
| Sept. 20 | Sunny | 27° /18° | 0 mm | 6 | |
| Sept. 21 | Patchy rain possible | 25° /17° | 0 mm | 4 | |
| Sept. 22 | Partly cloudy | 26° /15° | 0 mm | 5 | |
| Sept. 23 | Partly cloudy | 28° /16° | 0 mm | 6 | |
| Sept. 24 | Patchy rain possible | 23° /19° | 4.7 mm | 5 | |
| Sept. 25 | Sunny | 26° /16° | 0 mm | 6 | |
| Sept. 26 | Patchy rain possible | 27° /17° | 0.9 mm | 5 | |
| Sept. 27 |  Moderate rain | 25° /17° | 5.5 mm | 4 | |
| Sept. 28 | Patchy rain possible | 24° /16° | 1.2 mm | 4 | |
| Sept. 29 | Fog | 25° /21° | 0 mm | 5 | |
| Sept. 30 | Mist | 20° /18° | 0 mm | 5 | |
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Fairfax in September - FAQ
September rainfall patterns in Fairfax
UV exposure in Fairfax during September
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Where is Fairfax?Get accurate weather forecasts for Fairfax, located at latitude 38.846 and longitude -77.306. Stay updated with localized weather information tailored for Fairfax.