Washtenaw County (Ann Arbor)
September
Weather in Washtenaw County, Michigan for September 2026
Your guide to Washtenaw County weather in September - trends and predictions
In general, the average temperature in Washtenaw County at the beginning of September is 21 °F. As the month progressed, temperatures tended to moderately rise, reaching an average of 23 °F by the end of September.
Washtenaw County experiences moderate rainfall in September, with an average of 6 rainy days and a total precipitation of 107 mm.
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Temperatures
Rain 🌧️
More
24
Dry days
6
Rainy days
0
Snow days
24°/12°
Temperatures
17 km/h
Avg max wind
75 %
Avg humidity
Washtenaw County Weather September
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Temperatures trend during September in Washtenaw County
See the weather trend as well as the moving average line
September weather in Washtenaw County day by day
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| Date | Weather | Temperatures | Rain | UV | More |
|---|---|---|---|---|---|
| Sept. 1 |  Mist | 24° /12° | 0 mm | 5 | |
| Sept. 2 |  Sunny | 26° /13° | 0 mm | 7 | |
| Sept. 3 |  Cloudy | 25° /12° | 2.2 mm | 6 | |
| Sept. 4 |  Overcast | 17° /11° | 33.6 mm | 4 | |
| Sept. 5 | Overcast | 19° /7° | 0 mm | 4 | |
| Sept. 6 | Overcast | 17° /7° | 0 mm | 4 | |
| Sept. 7 | Overcast | 19° /8° | 0 mm | 4 | |
| Sept. 8 | Sunny | 22° /6° | 0 mm | 6 | |
| Sept. 9 | Fog | 23° /6° | 0 mm | 5 | |
| Sept. 10 | Overcast | 22° /12° | 0 mm | 5 | |
| Sept. 11 | Cloudy | 27° /15° | 0 mm | 6 | |
| Sept. 12 | Overcast | 27° /13° | 0 mm | 6 | |
| Sept. 13 | Mist | 25° /10° | 0 mm | 6 | |
| Sept. 14 | Fog | 28° /13° | 0 mm | 6 | |
| Sept. 15 | Fog | 28° /13° | 0 mm | 6 | |
| Sept. 16 | Mist | 27° /14° | 0 mm | 6 | |
| Sept. 17 | Mist | 25° /14° | 0 mm | 6 | |
| Sept. 18 | Fog | 30° /10° | 0 mm | 7 | |
| Sept. 19 | Fog | 22° /16° | 0 mm | 5 | |
| Sept. 20 |  Partly cloudy | 26° /14° | 0 mm | 7 | |
| Sept. 21 |  Moderate or heavy rain shower | 23° /16° | 48.4 mm | 5 | |
| Sept. 22 |  Light rain | 26° /18° | 6.4 mm | 6 | |
| Sept. 23 | Mist | 24° /18° | 0 mm | 5 | |
| Sept. 24 | Fog | 21° /16° | 5.7 mm | 5 | |
| Sept. 25 |  Light rain shower | 19° /15° | 10.7 mm | 4 | |
| Sept. 26 | Fog | 22° /10° | 0 mm | 5 | |
| Sept. 27 | Overcast | 27° /15° | 0 mm | 6 | |
| Sept. 28 | Sunny | 24° /15° | 0 mm | 6 | |
| Sept. 29 | Sunny | 25° /11° | 0 mm | 7 | |
| Sept. 30 | Partly cloudy | 23° /12° | 0 mm | 6 | |
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Important Notice
Our weather forecast for Washtenaw 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 Washtenaw County forecast closer to your planned date for the most up-to-date weather information.
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Washtenaw County in September - FAQ
What are the expected maximum and minimum temperatures in Washtenaw County during September?
Enjoy moderate daytime temperatures of up to 24° and cooler nights around 12°. Ideal for a range of outdoor activities, from hiking to city tours.
How much rainfall should be expected in Washtenaw County during September?
Significant rainfall exceeding 107 mm is expected in Washtenaw County during September, occurring over more than 6 days. Preparing for wet conditions is recommended in your planning.
What are the typical wind conditions in Washtenaw County during September?
The average wind speed in Washtenaw County during September is 17 km/h, suggesting breezy to windy conditions, depending on your activities.
September rainfall patterns in Washtenaw County
Explore the daily rainfall trends and prepare for Washtenaw Countys September weather 💧
Typically, Washtenaw County has 6 rainy days in September with a total of 107 mm of rainfall.
UV exposure in Washtenaw County during September
Stay informed about UV levels for safe outdoor activities throughout the month of September ☀️
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Where is Washtenaw County?Get accurate weather forecasts for Washtenaw County, located at latitude 42.278 and longitude -83.741. Stay updated with localized weather information tailored for Washtenaw County.
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