September
Weather in Delaware for September 2025
Your guide to Delaware weather in September - trends and predictions
Rip Current Statement - See hour by hour.
Until now, September 2025 in Delaware is slightly cooler than the historical average by -1.8 °F.
Expect cooler weather in the next days in Delaware with the forecast suggesting a temperature of 24.4 °F, lower than the historical average.
In general, the average temperature in Delaware at the beginning of September is 28.3 °F. As the month progressed, temperatures tended to significantly cool down, reaching an average of 22 °F by the end of September.
Delaware in September brings notable rainfall, with an average of 17 rainy days and a total precipitation of 223.9 mm.
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Temperatures
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13
Dry days
17
Rainy days
0
Snow days
25°/15°
Temperatures
15 km/h
Avg max wind
74 %
Avg humidity
Delaware Weather September
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Temperatures trend during September in Delaware
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September weather in Delaware day by day
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| Date | Weather | Temperatures | Rain | UV | More |
|---|---|---|---|---|---|
| Sept. 1 |  Sunny | 27° /16° | 1.5 mm | 6 | |
| Sept. 2 | Sunny | 27° /15° | 0 mm | 6 | |
| Sept. 3 |  Partly cloudy | 26° /14° | 0 mm | 6 | |
| Sept. 4 |  Thundery outbreaks possible | 30° /16° | 0 mm | 6 | |
| Sept. 5 |  Cloudy | 31° /18° | 6.1 mm | 7 | |
| Sept. 6 | Sunny | 31° /20° | 7.4 mm | 7 | |
| Sept. 7 | Thundery outbreaks possible | 26° /16° | 25.9 mm | 6 | |
| Sept. 8 | Sunny | 27° /13° | 2.2 mm | 7 | |
| Sept. 9 | Thundery outbreaks possible | 26° /14° | 5.4 mm | 6 | |
| Sept. 10 |  Moderate or heavy rain shower | 26° /16° | 4.7 mm | 6 | |
| Sept. 11 |  Light rain shower | 27° /16° | 1.9 mm | 7 | |
| Sept. 12 | Moderate rain at times | 28° /16° | 1.2 mm | 7 | |
| Sept. 13 |  Torrential rain shower | 26° /16° | 7.9 mm | 6 | |
| Sept. 14 | Sunny | 28° /16° | 0 mm | 7 | |
| Sept. 15 |  Overcast | 27° /16° | 0 mm | 1.2 | |
| Sept. 16 | Patchy rain possible | 19° /16° | 0.2 mm | 1 | |
| Sept. 17 | Overcast | 19° /15° | 0 mm | 0.2 | |
| Sept. 18 | Patchy rain possible | 28° /16° | 4 mm | 1.4 | |
| Sept. 19 | Sunny | 31° /18° | 0 mm | 0 | |
| Sept. 20 | Sunny | 25° /16° | 0 mm | 6 | |
| Sept. 21 | Sunny | 24° /14° | 0 mm | 5 | |
| Sept. 22 | Sunny | 26° /14° | 0 mm | 5 | |
| Sept. 23 | Sunny | 27° /15° | 0 mm | 6 | |
| Sept. 24 |  Moderate rain | 24° /17° | 5.5 mm | 5 | |
| Sept. 25 | Patchy rain possible | 25° /19° | 1.5 mm | 5 | |
| Sept. 26 | Moderate rain | 27° /17° | 10.7 mm | 5 | |
| Sept. 27 | Moderate rain | 20° /16° | 19 mm | 4 | |
| Sept. 28 | Patchy rain possible | 19° /14° | 0.5 mm | 4 | |
| Sept. 29 | Light rain shower | 18° /15° | 20.7 mm | 5 | |
| Sept. 30 |  Light rain | 21° /15° | 0.7 mm | 5 | |
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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 15°, suitable for diverse activities and preferences.
How much rainfall should be expected in Delaware during September?
Significant rainfall exceeding 223.9 mm is expected in Delaware during September, occurring over more than 17 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 15 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 💧
UV exposure in Delaware during September
Stay informed about UV levels for safe outdoor activities throughout the month of September ☀️
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