Washington
September
Weather in Washington for September 2025
Your guide to Washington weather in September - trends and predictions
In general, the average temperature in Washington at the beginning of September is 30.1 °F. As the month progressed, temperatures tended to significantly cool down, reaching an average of 21.6 °F by the end of September.
The climate of Washington in September is notably wet, with an average of 14 rainy days.
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16
Dry days
14
Rainy days
0
Snow days
27°/16°
Temperatures
13 km/h
Avg max wind
69 %
Avg humidity
Washington in September average weather
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| Mon. | Tue. | Wed. | Thu. | Fri. | Sat. | Sun. |
|---|---|---|---|---|---|---|
| 1  29° | 2 28° | 3  30° | 4  31° | 5 32° | 6 32° | 7  29° |
| 8 28° | 9 29° | 10 30° | 11 31° | 12  29° | 13 28° | 14 27° |
| 15 27° | 16 26° | 17  21° | 18  22° | 19 23° | 20 27° | 21 26° |
| 22 22° | 23 20° | 24 19° | 25 21° | 26 22° | 27 21° | 28  24° |
| 29  22° | 30 22° |
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Temperatures trend during September in Washington
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 | 29° /17° | 0.5 mm | 7 | |
| Sept. 2 | Sunny | 28° /16° | 0 mm | 8 | |
| Sept. 3 | Partly cloudy | 30° /15° | 0 mm | 8 | |
| Sept. 4 | Patchy rain possible | 31° /18° | 0.2 mm | 7 | |
| Sept. 5 | Sunny | 32° /19° | 0 mm | 8 | |
| Sept. 6 | Sunny | 32° /19° | 0.4 mm | 8 | |
| Sept. 7 | Thundery outbreaks possible | 29° /18° | 0.4 mm | 7 | |
| Sept. 8 | Partly cloudy | 28° /15° | 2.9 mm | 7 | |
| Sept. 9 | Light rain shower | 29° /15° | 2.9 mm | 7 | |
| Sept. 10 | Light rain shower | 30° /16° | 6.3 mm | 7 | |
| Sept. 11 | Patchy rain possible | 31° /17° | 0.6 mm | 8 | |
| Sept. 12 | Mist | 29° /18° | 0 mm | 7 | |
| Sept. 13 | Light rain shower | 28° /17° | 2.2 mm | 7 | |
| Sept. 14 | Sunny | 27° /17° | 0 mm | 7 | |
| Sept. 15 | Sunny | 27° /14° | 0 mm | 7 | |
| Sept. 16 | Sunny | 26° /14° | 5.6 mm | 6 | |
| Sept. 17 | Heavy rain | 21° /17° | 18.8 mm | 5 | |
| Sept. 18 | Light rain | 22° /17° | 19.5 mm | 5 | |
| Sept. 19 | Sunny | 23° /16° | 0 mm | 6 | |
| Sept. 20 | Partly cloudy | 27° /16° | 0 mm | 7 | |
| Sept. 21 | Partly cloudy | 26° /17° | 12.4 mm | 6 | |
| Sept. 22 | Patchy rain possible | 22° /16° | 5.5 mm | 5 | |
| Sept. 23 | Heavy rain | 20° /15° | 34.2 mm | 5 | |
| Sept. 24 | Light rain shower | 19° /17° | 48.6 mm | 4 | |
| Sept. 25 | Patchy rain possible | 21° /16° | 3.3 mm | 5 | |
| Sept. 26 | Fog | 22° /18° | 7.5 mm | 5 | |
| Sept. 27 | Patchy rain possible | 21° /17° | 20 mm | 5 | |
| Sept. 28 | Overcast | 24° /16° | 2.8 mm | 6 | |
| Sept. 29 | Moderate or heavy rain shower | 22° /18° | 1.7 mm | 5 | |
| Sept. 30 | Patchy rain possible | 22° /16° | 0.6 mm | 5 | |
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Important Notice
Our weather forecast for Washington 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 Washington forecast closer to your planned date for the most up-to-date weather information.
Washington in September - FAQ
What are the expected maximum and minimum temperatures in Washington during September?
During September, expect a variety of temperatures with highs around 27° and lows near 16°, suitable for diverse activities and preferences.
How much rainfall should be expected in Washington during September?
Significant rainfall exceeding 161.8 mm is expected in Washington during September, occurring over more than 14 days. Preparing for wet conditions is recommended in your planning.
What are the typical wind conditions in Washington during September?
The average wind speed in Washington during September is 13 km/h, suggesting breezy to windy conditions, depending on your activities.
September rainfall patterns in Washington
Explore the daily rainfall trends and prepare for Washingtons September weather 💧
UV exposure in Washington during September
Stay informed about UV levels for safe outdoor activities throughout the month of September ☀️
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