Fairfax County (Herndon)
September
Weather in Fairfax County, Virginia for September 2027
Your guide to Fairfax County weather in September - trends and predictions
The climate of Fairfax County in September is notably wet, with an average of 11 rainy days, and a total of 190.6 mm of precipitation.
Is September a good time to visit Fairfax County? check out the best time to travel to Fairfax County page.
✨ Is September a good time to visit Fairfax County? – Ask the AI Weatherman
Rain 🌧️
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19
Dry days
11
Rainy days
0
Snow days
27°/17°
Temperatures
14 km/h
Avg max wind
69 %
Avg humidity
Fairfax County Weather September
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Temperatures trend during September in Fairfax County
See the weather trend as well as the moving average line
September weather in Fairfax County day by day
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| Date | Weather | Temperatures | Rain | UV | More |
|---|---|---|---|---|---|
| Sept. 1 |  Cloudy | 32° /18° | 0 mm | 8.6 | |
| Sept. 2 |  Light rain | 31° /19° | 3 mm | 8 | |
| Sept. 3 |  Partly cloudy | 31° /19° | 0 mm | 8.4 | |
| Sept. 4 | Light rain | 34° /20° | 8.5 mm | 8.3 | |
| Sept. 5 |  Patchy rain possible | 31° /20° | 1.7 mm | 7 | |
| Sept. 6 |  Heavy rain | 30° /19° | 55 mm | 8 | |
| Sept. 7 |  Overcast | 27° /16° | 0 mm | 6 | |
| Sept. 8 |  Sunny | 28° /13° | 0 mm | 7.9 | |
| Sept. 9 | Partly cloudy | 28° /15° | 0 mm | 6 | |
| Sept. 10 | Patchy rain possible | 27° /18° | 1.6 mm | 4 | |
| Sept. 11 | Cloudy | 26° /18° | 0.2 mm | 5 | |
| Sept. 12 | Patchy rain possible | 29° /17° | 1.6 mm | 5 | |
| Sept. 13 | Patchy rain possible | 29° /19° | 1.6 mm | 5 | |
| Sept. 14 | Cloudy | 28° /18° | 0 mm | 7 | |
| Sept. 15 | Overcast | 27° /16° | 0.8 mm | 7 | |
| Sept. 16 | Overcast | 26° /16° | 0 mm | 5 | |
| Sept. 17 | Heavy rain | 23° /17° | 38.4 mm | 4 | |
| Sept. 18 |  Mist | 28° /19° | 0.4 mm | 5 | |
| Sept. 19 | Patchy rain possible | 30° /18° | 1 mm | 6 | |
| Sept. 20 | Light rain | 25° /18° | 8.7 mm | 2 | |
| Sept. 21 | Light rain | 22° /17° | 6.7 mm | 2 | |
| Sept. 22 | Light rain | 22° /14° | 8.1 mm | 4 | |
| Sept. 23 |  Thundery outbreaks possible | 24° /15° | 17.9 mm | 3 | |
| Sept. 24 | Partly cloudy | 24° /15° | 0 mm | 4 | |
| Sept. 25 |  Moderate rain | 24° /14° | 11.9 mm | 3 | |
| Sept. 26 | Moderate rain | 24° /16° | 12.6 mm | 4 | |
| Sept. 27 | Patchy rain possible | 22° /15° | 2 mm | 3 | |
| Sept. 28 | Light rain | 20° /16° | 8.4 mm | 1 | |
| Sept. 29 | Fog | 25° /16° | 0.1 mm | 2 | |
| Sept. 30 | Overcast | 26° /16° | 0 mm | 3 | |
| Next | |||||
Important Notice
Our weather forecast for Fairfax County 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 Fairfax County forecast closer to your planned date for the most up-to-date weather information.
Change Month
Fairfax County in September - FAQ
What are the expected maximum and minimum temperatures in Fairfax County during September?
During September, expect a variety of temperatures with highs around 27° and lows near 17°, suitable for diverse activities and preferences.
How much rainfall should be expected in Fairfax County during September?
Significant rainfall exceeding 190.6 mm is expected in Fairfax County during September, occurring over more than 11 days. Preparing for wet conditions is recommended in your planning.
What are the typical wind conditions in Fairfax County during September?
The average wind speed in Fairfax County during September is 14 km/h, suggesting breezy to windy conditions, depending on your activities.
September rainfall patterns in Fairfax County
Explore the daily rainfall trends and prepare for Fairfax Countys September weather 💧
Typically, Fairfax County has 11 rainy days in September with a total of 190.6 mm of rainfall.
UV exposure in Fairfax County during September
Stay informed about UV levels for safe outdoor activities throughout the month of September ☀️
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