Delaware (Wilmington)
September
Weather in Delaware for September 2026
Your guide to Delaware weather in September - trends and predictions
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Until now, September 2026 in Delaware has been nearly identical to the historical average, with a temperature of 26.1 °F (showing only a slight deviation of 0.2 °F).
The forecast for the next days in Delaware predicts temperatures to be around 20 °F, close to the historical average.
In general, the average temperature in Delaware at the beginning of September is 28.1 °F. As the month progressed, temperatures tended to significantly cool down, reaching an average of 21.1 °F by the end of September.
Delaware experiences moderate rainfall in September, with an average of 8 rainy days and a total precipitation of 219.9 mm.
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Temperatures
Rain 🌧️
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22
Dry days
8
Rainy days
0
Snow days
25°/17°
Temperatures
13 km/h
Avg max wind
71 %
Avg humidity
Delaware Weather September
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What’s the Weather Like in Delaware This September?
Discover the average temperatures and weather trends across Delaware’s cities this September.
Temperatures trend during September in Delaware
See the weather trend as well as the moving average line
September weather in Delaware day by day
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| Date | Weather | Temperatures | Rain | UV | More |
|---|---|---|---|---|---|
| Sept. 1 |  Overcast | 30° /19° | 0.2 mm | 4 | |
| Sept. 2 |  Sunny | 26° /18° | 2.9 mm | 5 | |
| Sept. 3 | Overcast | 27° /18° | 5.7 mm | 4 | |
| Sept. 4 |  Mist | 30° /18° | 1 mm | 8 | |
| Sept. 5 | Mist | 30° /19° | 11.3 mm | 7 | |
| Sept. 6 |  Light rain shower | 30° /18° | 10.9 mm | 8 | |
| Sept. 7 |  Moderate or heavy rain shower | 24° /14° | 40.8 mm | 6 | |
| Sept. 8 | Sunny | 26° /13° | 0 mm | 8 | |
| Sept. 9 |  Cloudy | 27° /16° | 0 mm | 7 | |
| Sept. 10 | Overcast | 26° /19° | 0.1 mm | 3 | |
| Sept. 11 |  Partly cloudy | 28° /18° | 1.5 mm | 4 | |
| Sept. 12 | Partly cloudy | 26° /15° | 0 mm | 6 | |
| Sept. 13 | Mist | 27° /18° | 8.1 mm | 5 | |
| Sept. 14 | Overcast | 26° /17° | 0.3 mm | 7 | |
| Sept. 15 | Moderate rain at times | 25° /15° | 1.8 mm | 7 | |
| Sept. 16 | Overcast | 26° /15° | 0 mm | 7 | |
| Sept. 17 | Moderate rain at times | 24° /17° | 11.7 mm | 3 | |
| Sept. 18 | Overcast | 27° /19° | 0.4 mm | 4 | |
| Sept. 19 | Partly cloudy | 27° /17° | 0 mm | 5 | |
| Sept. 20 | Overcast | 22° /16° | 9.8 mm | 2 | |
| Sept. 21 | Overcast | 22° /15° | 0.8 mm | 2 | |
| Sept. 22 | Overcast | 21° /14° | 6.2 mm | 2 | |
| Sept. 23 | Fog | 24° /15° | 0.8 mm | 2 | |
| Sept. 24 | Mist | 23° /14° | 0 mm | 3 | |
| Sept. 25 | Light rain shower | 23° /15° | 20.2 mm | 1 | |
| Sept. 26 | Mist | 21° /16° | 9.8 mm | 3 | |
| Sept. 27 | Patchy rain possible | 16° /13° | 36.4 mm | 0.5 | |
| Sept. 28 | Patchy rain possible | 18° /14° | 4.1 mm | 0.6 | |
| Sept. 29 | Overcast | 22° /16° | 0 mm | 4.5 | |
| Sept. 30 | Sunny | 25° /16° | 0 mm | 5.3 | |
| Next | |||||
Important Notice
Our weather forecast for Delaware 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 Delaware forecast closer to your planned date for the most up-to-date weather information.
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Delaware in September - FAQ
What are the expected maximum and minimum temperatures in Delaware 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 Delaware during September?
Significant rainfall exceeding 219.9 mm is expected in Delaware during September, occurring over more than 8 days. Preparing for wet conditions is recommended in your planning.
What are the typical wind conditions in Delaware during September?
The average wind speed in Delaware during September is 13 km/h, suggesting breezy to windy conditions, depending on your activities.
September rainfall patterns in Delaware
Explore the daily rainfall trends and prepare for Delawares September weather 💧
Typically, Delaware has 8 rainy days in September with a total of 219.9 mm of rainfall.
UV exposure in Delaware during September
Stay informed about UV levels for safe outdoor activities throughout the month of September ☀️
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