Delaware County (Glen Mills)
September
Weather in Delaware County for September 2025
Your guide to Delaware County weather in September - trends and predictions
In general, the average temperature in Delaware County at the beginning of September is 23.4 °F. As the month progressed, temperatures tended to noticeably cool down, reaching an average of 20.6 °F by the end of September.
Delaware County sees moderate rainfall in September, averaging 9 rainy days.
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Temperatures
Rain 🌧️
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21
Dry days
9
Rainy days
0
Snow days
23°/15°
Temperatures
15 km/h
Avg max wind
73 %
Avg humidity
Delaware County in September average weather
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| Mon. | Tue. | Wed. | Thu. | Fri. | Sat. | Sun. |
|---|---|---|---|---|---|---|
| 1  27° | 2  23° | 3  22° | 4 24° | 5  26° | 6 22° | 7  20° |
| 8 20° | 9 24° | 10 26° | 11 27° | 12 27° | 13 26° | 14 28° |
| 15 27° | 16 25° | 17 21° | 18 20° | 19  19° | 20 21° | 21  25° |
| 22  20° | 23 21° | 24 19° | 25 19° | 26 27° | 27 23° | 28 20° |
| 29 18° | 30  18° |
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Temperatures trend during September in Delaware County
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 | Light rain shower | 27° /20° | 2.9 mm | 6 | |
| Sept. 2 | Overcast | 23° /15° | 0 mm | 5 | |
| Sept. 3 | Sunny | 22° /11° | 0 mm | 6 | |
| Sept. 4 | Overcast | 24° /12° | 0 mm | 5 | |
| Sept. 5 | Partly cloudy | 26° /13° | 0 mm | 7 | |
| Sept. 6 | Light rain shower | 22° /16° | 0.4 mm | 5 | |
| Sept. 7 | Fog | 20° /12° | 0.9 mm | 5 | |
| Sept. 8 | Sunny | 20° /9° | 0 mm | 6 | |
| Sept. 9 | Sunny | 24° /11° | 0 mm | 6 | |
| Sept. 10 | Sunny | 26° /14° | 0 mm | 7 | |
| Sept. 11 | Sunny | 27° /14° | 0 mm | 7 | |
| Sept. 12 | Sunny | 27° /15° | 0 mm | 7 | |
| Sept. 13 | Partly cloudy | 26° /15° | 0 mm | 7 | |
| Sept. 14 | Partly cloudy | 28° /17° | 0 mm | 7 | |
| Sept. 15 | Partly cloudy | 27° /16° | 0 mm | 7 | |
| Sept. 16 | Overcast | 25° /14° | 0 mm | 6 | |
| Sept. 17 | Overcast | 21° /17° | 0 mm | 5 | |
| Sept. 18 | Mist | 20° /17° | 0 mm | 5 | |
| Sept. 19 | Heavy rain | 19° /16° | 156.7 mm | 4 | |
| Sept. 20 | Overcast | 21° /18° | 0 mm | 5 | |
| Sept. 21 | Moderate or heavy rain shower | 25° /18° | 44.5 mm | 5 | |
| Sept. 22 | Thundery outbreaks possible | 20° /17° | 0 mm | 5 | |
| Sept. 23 | Overcast | 21° /14° | 0 mm | 5 | |
| Sept. 24 | Moderate or heavy rain shower | 19° /16° | 18.9 mm | 4 | |
| Sept. 25 | Moderate or heavy rain shower | 19° /17° | 27.8 mm | 4 | |
| Sept. 26 | Fog | 27° /20° | 0 mm | 6 | |
| Sept. 27 | Fog | 23° /19° | 0 mm | 5 | |
| Sept. 28 | Light rain shower | 20° /17° | 11.7 mm | 5 | |
| Sept. 29 | Overcast | 18° /16° | 0 mm | 4 | |
| Sept. 30 | Light rain | 18° /15° | 6.7 mm | 4 | |
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Important Notice
Our weather forecast for Delaware 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 Delaware County forecast closer to your planned date for the most up-to-date weather information.
Delaware County in September - FAQ
What are the expected maximum and minimum temperatures in Delaware County during September?
During September, expect a variety of temperatures with highs around 23° and lows near 15°, suitable for diverse activities and preferences.
How much rainfall should be expected in Delaware County during September?
Significant rainfall exceeding 270.5 mm is expected in Delaware County during September, occurring over more than 9 days. Preparing for wet conditions is recommended in your planning.
What are the typical wind conditions in Delaware County during September?
The average wind speed in Delaware County during September is 15 km/h, suggesting breezy to windy conditions, depending on your activities.
September rainfall patterns in Delaware County
Explore the daily rainfall trends and prepare for Delaware Countys September weather 💧
UV exposure in Delaware County during September
Stay informed about UV levels for safe outdoor activities throughout the month of September ☀️
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Where is Delaware County?Get accurate weather forecasts for Delaware County, located at latitude 39.919 and longitude -75.492. Stay updated with localized weather information tailored for Delaware County.
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