Weather in Philadelphia, Pennsylvania for September 2025
Until now, September 2025 in Philadelphia is slightly cooler than the historical average by -1.8 °F.
Expect cooler weather in the next days in Philadelphia with the forecast suggesting a temperature of 26.3 °F, lower than the historical average.
In general, the average temperature in Philadelphia at the beginning of September is 27.7 °F. As the month progressed, temperatures tended to significantly cool down, reaching an average of 21.9 °F by the end of September.
Philadelphia in September brings notable rainfall, with an average of 20 rainy days and a total precipitation of 121.2 mm.
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Philadelphia Weather September
Temperatures trend during September in Philadelphia
September weather in Philadelphia day by day
| Date | Weather | Temperatures | Rain | UV | More |
|---|---|---|---|---|---|
| Sept. 1 |  Sunny | 27° /18° | 6.4 mm | 6 | |
| Sept. 2 |  Overcast | 27° /17° | 1.7 mm | 7 | |
| Sept. 3 | Sunny | 27° /16° | 0 mm | 6 | |
| Sept. 4 | Sunny | 29° /18° | 0 mm | 7 | |
| Sept. 5 |  Cloudy | 29° /19° | 5.1 mm | 7 | |
| Sept. 6 | Overcast | 29° /20° | 14.6 mm | 6 | |
| Sept. 7 |  Partly cloudy | 26° /18° | 11.5 mm | 6 | |
| Sept. 8 |  Patchy rain possible | 27° /17° | 1.5 mm | 6 | |
| Sept. 9 | Sunny | 27° /16° | 2.4 mm | 6 | |
| Sept. 10 | Sunny | 27° /17° | 0.2 mm | 7 | |
| Sept. 11 | Sunny | 27° /17° | 6.7 mm | 6 | |
| Sept. 12 | Sunny | 29° /18° | 3.2 mm | 7 | |
| Sept. 13 | Partly cloudy | 30° /17° | 0 mm | 1.2 | |
| Sept. 14 | Partly cloudy | 31° /18° | 0.1 mm | 0.7 | |
| Sept. 15 | Partly cloudy | 27° /20° | 0 mm | 1.3 | |
| Sept. 16 | Sunny | 29° /18° | 0 mm | 1.3 | |
| Sept. 17 | Partly cloudy | 26° /19° | 0 mm | 0 | |
| Sept. 18 | Sunny | 29° /18° | 0 mm | 6 | |
| Sept. 19 | Sunny | 32° /19° | 0 mm | 7 | |
| Sept. 20 | Patchy rain possible | 33° /21° | 0.6 mm | 6 | |
| Sept. 21 | Patchy rain possible | 30° /16° | 0.3 mm | 5 | |
| Sept. 22 | Overcast | 17° /14° | 0 mm | 4 | |
| Sept. 23 |  Moderate rain | 15° /14° | 11.1 mm | 3 | |
| Sept. 24 | Patchy rain possible | 19° /16° | 0.4 mm | 4 | |
| Sept. 25 | Patchy rain possible | 25° /17° | 0.1 mm | 5 | |
| Sept. 26 | Cloudy | 25° /18° | 0 mm | 5 | |
| Sept. 27 | Overcast | 23° /15° | 0 mm | 5 | |
| Sept. 28 |  Moderate or heavy rain shower | 21° /13° | 3 mm | 5 | |
| Sept. 29 | Partly cloudy | 20° /13° | 17.8 mm | 5 | |
| Sept. 30 | Sunny | 20° /14° | 1.7 mm | 5 | |
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Philadelphia in September - FAQ
September rainfall patterns in Philadelphia
UV exposure in Philadelphia during September
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Where is Philadelphia?Get accurate weather forecasts for Philadelphia, located at latitude 39.952 and longitude -75.164. Stay updated with localized weather information tailored for Philadelphia.