Philadelphia, Pennsylvania weather in September

Averages from 2021–2025 (150 days of record).

Average high: 79°F
Average low: 62°F
Rainy days: ~10 per month
Total precipitation: 4.0 in
Warmest recorded: 98°F
Coldest recorded: 48°F

Expect September days in Philadelphia, Pennsylvania to top out around 79°F and cool to about 62°F overnight, with roughly 10 days of measurable rain across the month. In recent years September has ranged from 48°F to 98°F.

Other months

January February March April May June July August October November December

Current Philadelphia, Pennsylvania forecast → · Historical data by Open-Meteo (ERA5).