Weather history and climate summary information is available for the following locations:
- Allentown
- Erie
- Harrisburg
- Philadelphia
- Pittsburgh
- Pittsburgh (pennsylva)
- Scranton
Warmest September Days
The warmest September days in Pennsylvania are:
| Allentown, Pennsylvania | 1980 | 99°F |
| Philadelphia, Pennsylvania | 1973 | 98.6°F |
| Philadelphia, Pennsylvania | 1983 | 98.1°F |
| Philadelphia, Pennsylvania | 1980 | 98.1°F |
| Pittsburgh (pennsylva), Pennsylvania | 1954 | 97°F |
Coldest September Days
The coldest September days in Pennsylvania were:
| Scranton, Pennsylvania | 2000 | 28.9°F |
| Scranton, Pennsylvania | 1974 | 30°F |
| Allentown, Pennsylvania | 1974 | 32°F |
| Allentown, Pennsylvania | 2000 | 32°F |
| Philadelphia, Pennsylvania | 1983 | 32.7°F |
Wettest September Days
The wettest single days in September occurred:
| Allentown, Pennsylvania | 1985 | 7.8 inches |
| Allentown, Pennsylvania | 1999 | 5.6 inches |
| Philadelphia, Pennsylvania | 1999 | 5.4 inches |
| Erie, Pennsylvania | 1979 | 4.8 inches |
| Philadelphia, Pennsylvania | 1985 | 4.8 inches |