‹ Pennsylvania weather by month
Pennsylvania weather in September
One place stands in for Pennsylvania here — these are Philadelphia's numbers, not a statewide average.
Based on 1 weather station, in Philadelphia. One station — Philadelphia holds down the state’s mild southeast corner; the mountains and the Erie snowbelt are a different, colder Pennsylvania.
Philadelphia
Highs near 79°, nights around 61°, and 4.4 in of rain in a typical September.
| Place | Highs / lows | Wet days | The short version |
|---|---|---|---|
| Philadelphia | 79° / 61° | 6 | Best month of the year, quietly. Don't tell anyone. |
Each place above has its own page for the full story — what the month feels like, what to pack, and whether the timing is right.