Prince William County (Haymarket)
September
Weather in Prince William County, Virginia for September 2026
Your guide to Prince William County weather in September - trends and predictions
So far, September 2026 in Prince William County shows a warmer trend than usual by 2.6 °F.
Expect cooler weather in the next days in Prince William County with the forecast suggesting a temperature of 26.4 °F, lower than the historical average.
In general, the average temperature in Prince William County at the beginning of September is 30.4 °F. As the month progressed, temperatures tended to significantly cool down, reaching an average of 25.9 °F by the end of September.
Prince William County experiences moderate rainfall in September, with an average of 9 rainy days and a total precipitation of 224 mm.
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Temperatures
Rain 🌧️
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21
Dry days
9
Rainy days
0
Snow days
25°/17°
Temperatures
12 km/h
Avg max wind
69 %
Avg humidity
Prince William County Weather September
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Temperatures trend during September in Prince William County
See the weather trend as well as the moving average line
September weather in Prince William County day by day
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| Date | Weather | Temperatures | Rain | UV | More |
|---|---|---|---|---|---|
| Sept. 1 |  Overcast | 31° /17° | 0 mm | 9 | |
| Sept. 2 | Overcast | 31° /18° | 15.7 mm | 8 | |
| Sept. 3 |  Cloudy | 31° /18° | 0.1 mm | 8 | |
| Sept. 4 | Cloudy | 33° /19° | 2.4 mm | 8 | |
| Sept. 5 |  Mist | 30° /18° | 0.6 mm | 6 | |
| Sept. 6 |  Moderate or heavy rain shower | 30° /19° | 14.8 mm | 8 | |
| Sept. 7 | Overcast | 27° /15° | 5.7 mm | 6 | |
| Sept. 8 |  Sunny | 27° /12° | 0 mm | 8 | |
| Sept. 9 |  Partly cloudy | 28° /15° | 0 mm | 6 | |
| Sept. 10 | Overcast | 27° /18° | 0.2 mm | 4 | |
| Sept. 11 | Cloudy | 26° /17° | 24.8 mm | 5 | |
| Sept. 12 | Sunny | 28° /17° | 1.5 mm | 5 | |
| Sept. 13 | Sunny | 29° /17° | 2.3 mm | 4 | |
| Sept. 14 | Partly cloudy | 28° /17° | 0 mm | 7 | |
| Sept. 15 | Cloudy | 27° /16° | 0 mm | 7 | |
| Sept. 16 | Sunny | 29° /14° | 0 mm | 7 | |
| Sept. 17 | Sunny | 30° /17° | 2 mm | 7.1 | |
| Sept. 18 |  Patchy rain possible | 28° /21° | 0.8 mm | 5.5 | |
| Sept. 19 | Overcast | 26° /20° | 0.2 mm | 6.9 | |
| Sept. 20 | Light rain shower | 27° /19° | 3 mm | 6 | |
| Sept. 21 | Fog | 23° /20° | 3.7 mm | 5 | |
| Sept. 22 | Light rain shower | 24° /20° | 9.8 mm | 5 | |
| Sept. 23 | Patchy rain possible | 27° /19° | 8.4 mm | 6 | |
| Sept. 24 | Mist | 29° /18° | 0.6 mm | 7 | |
| Sept. 25 | Partly cloudy | 21° /14° | 0.4 mm | 6 | |
| Sept. 26 | Sunny | 24° /15° | 0 mm | 6 | |
| Sept. 27 | Sunny | 26° /15° | 0 mm | 7 | |
| Sept. 28 | Fog | 27° /16° | 0 mm | 7 | |
| Sept. 29 | Sunny | 29° /16° | 0 mm | 7 | |
| Sept. 30 | Overcast | 25° /18° | 3.6 mm | 1 | |
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Important Notice
Our weather forecast for Prince William 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 Prince William County forecast closer to your planned date for the most up-to-date weather information.
Change Month
Prince William County in September - FAQ
What are the expected maximum and minimum temperatures in Prince William County during September?
During September, expect a variety of temperatures with highs around 25° and lows near 17°, suitable for diverse activities and preferences.
How much rainfall should be expected in Prince William County during September?
Significant rainfall exceeding 224 mm is expected in Prince William County during September, occurring over more than 9 days. Preparing for wet conditions is recommended in your planning.
What are the typical wind conditions in Prince William County during September?
The average wind speed in Prince William County during September is 12 km/h, suggesting breezy to windy conditions, depending on your activities.
September rainfall patterns in Prince William County
Explore the daily rainfall trends and prepare for Prince William Countys September weather 💧
Typically, Prince William County has 9 rainy days in September with a total of 224 mm of rainfall.
UV exposure in Prince William County during September
Stay informed about UV levels for safe outdoor activities throughout the month of September ☀️
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Where is Prince William County?Get accurate weather forecasts for Prince William County, located at latitude 38.812 and longitude -77.636. Stay updated with localized weather information tailored for Prince William County.
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