Washington (Seattle)
September
Weather in Washington for September 2027
Your guide to Washington weather in September - trends and predictions
In general, the average temperature in Washington at the beginning of September is 24.9 °C. As the month progressed, temperatures tended to significantly cool down, reaching an average of 18.5 °C by the end of September.
Washington experiences moderate rainfall in September, with an average of 6 rainy days and a total precipitation of 54.7 mm.
Is September a good time to visit Washington? check out the best time to travel to Washington page.
✨ Is September a good time to visit Washington? – Ask the AI Weatherman
Temperatures
Rain 🌧️
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24
Dry days
6
Rainy days
0
Snow days
21°/11°
Temperatures
12 km/h
Avg max wind
71 %
Avg humidity
Washington Weather September
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What’s the Weather Like in Washington This September?
Discover the average temperatures and weather trends across Washington’s cities this September.
Temperatures trend during September in Washington
See the weather trend as well as the moving average line
September weather in Washington day by day
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| Date | Weather | Temperatures | Rain | UV | More |
|---|---|---|---|---|---|
| Sept. 1 |  Partly cloudy | 24° /13° | 0 mm | 6 | |
| Sept. 2 |  Light rain | 26° /12° | 4.2 mm | 6 | |
| Sept. 3 |  Overcast | 23° /13° | 0.5 mm | 5 | |
| Sept. 4 |  Mist | 24° /13° | 0.2 mm | 6 | |
| Sept. 5 | Overcast | 26° /14° | 0.2 mm | 6 | |
| Sept. 6 |  Sunny | 26° /13° | 0.5 mm | 6 | |
| Sept. 7 | Partly cloudy | 25° /12° | 0 mm | 6 | |
| Sept. 8 | Partly cloudy | 24° /12° | 0.1 mm | 6 | |
| Sept. 9 | Overcast | 23° /13° | 0 mm | 5 | |
| Sept. 10 | Overcast | 24° /12° | 0 mm | 5 | |
| Sept. 11 | Overcast | 20° /14° | 0.7 mm | 4 | |
| Sept. 12 |  Patchy rain possible | 21° /13° | 1.2 mm | 4 | |
| Sept. 13 | Light rain | 20° /11° | 2.9 mm | 5 | |
| Sept. 14 | Patchy rain possible | 21° /11° | 2.1 mm | 4 | |
| Sept. 15 | Patchy rain possible | 21° /11° | 1 mm | 5 | |
| Sept. 16 | Overcast | 23° /10° | 0.5 mm | 5 | |
| Sept. 17 | Light rain | 20° /12° | 4.2 mm | 5 | |
| Sept. 18 | Patchy rain possible | 19° /11° | 1.9 mm | 4 | |
| Sept. 19 | Patchy rain possible | 19° /10° | 2.4 mm | 5 | |
| Sept. 20 |  Cloudy | 20° /10° | 0.8 mm | 4.9 | |
| Sept. 21 | Partly cloudy | 21° /9° | 0.5 mm | 4.8 | |
| Sept. 22 | Overcast | 21° /11° | 0 mm | 4.7 | |
| Sept. 23 | Patchy rain possible | 21° /12° | 1 mm | 4 | |
| Sept. 24 | Light rain | 21° /10° | 3 mm | 4.5 | |
| Sept. 25 | Light rain | 19° /11° | 6 mm | 4 | |
| Sept. 26 |  Moderate rain at times | 19° /10° | 6.2 mm | 4 | |
| Sept. 27 | Light rain | 20° /11° | 3.1 mm | 4.2 | |
| Sept. 28 | Light rain | 17° /10° | 3.5 mm | 4 | |
| Sept. 29 | Light rain | 16° /10° | 4 mm | 3 | |
| Sept. 30 | Light rain | 18° /9° | 3.9 mm | 4 | |
| Next | |||||
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.
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Washington in September - FAQ
What are the expected maximum and minimum temperatures in Washington during September?
Enjoy moderate daytime temperatures of up to 21° and cooler nights around 11°. Ideal for a range of outdoor activities, from hiking to city tours.
How much rainfall should be expected in Washington during September?
Moderate rainfall is anticipated in Washington during September, with a total of 54.7 mm spread over approximately 6 days. Considering plans for rainy days is advisable.
What are the typical wind conditions in Washington during September?
The average wind speed in Washington during September is 12 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 💧
Typically, Washington has 6 rainy days in September with a total of 54.7 mm of rainfall.
UV exposure in Washington during September
Stay informed about UV levels for safe outdoor activities throughout the month of September ☀️
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