Pennsylvania climate by month
January highs across Pennsylvania range from 36°F in Pittsburgh to 41°F in Philadelphia; July highs from 83°F in Pittsburgh to 88°F in Philadelphia. The most common best months across these cities are May, September.
Pennsylvania weather month by month
Average of the 4 Pennsylvania cities on this site, computed from NOAA's unrounded values (so it can differ by a degree from averaging the rounded city figures); individual cities differ, sometimes a lot.
| Month | High | Low | Wet days | Snow |
|---|---|---|---|---|
| January | 39°F | 23°F | 12 | 9.7 in |
| February | 42°F | 24°F | 11 | 9.9 in |
| March | 51°F | 31°F | 11 | 5.6 in |
| April | 63°F | 42°F | 12 | 0.5 in |
| May | 73°F | 52°F | 13 | 0.0 in |
| June | 81°F | 61°F | 11 | 0.0 in |
| July | 86°F | 66°F | 11 | 0.0 in |
| August | 84°F | 64°F | 10 | 0.0 in |
| September | 77°F | 57°F | 10 | 0.0 in |
| October | 65°F | 45°F | 10 | 0.2 in |
| November | 53°F | 35°F | 10 | 1.0 in |
| December | 43°F | 28°F | 12 | 4.8 in |
Regional differences
- Warmest winterPhiladelphia: January high 41°F
- Coolest summerPittsburgh: July high 83°F
- Most wet daysPittsburgh: 154 a year
- Fewest wet daysPhiladelphia: 121 a year
- Most snowPittsburgh: 44.1 in a year
Warmest and coolest Pennsylvania city each month
| Month | Warmest | Coolest | Best month for |
|---|---|---|---|
| January | Philadelphia 41°F | Pittsburgh 36°F | – |
| February | Philadelphia 44°F | Pittsburgh 40°F | – |
| March | Philadelphia 53°F | Pittsburgh 49°F | – |
| April | Philadelphia 65°F | Gettysburg 62°F | – |
| May | Philadelphia 74°F | Pittsburgh 72°F | 4 cities |
| June | Philadelphia 83°F | Pittsburgh 79°F | – |
| July | Philadelphia 88°F | Pittsburgh 83°F | – |
| August | Philadelphia 86°F | Pittsburgh 82°F | – |
| September | Philadelphia 79°F | Pittsburgh 75°F | 1 city |
| October | Philadelphia 67°F | Pittsburgh 63°F | – |
| November | Philadelphia 56°F | Pittsburgh 51°F | – |
| December | Philadelphia 46°F | Pittsburgh 41°F | – |
By normal daily high. "Best month for": how many of the 4 cities have it among their best months by our comfort score.
Frost and humidity across Pennsylvania
- Earliest typical last frostPhiladelphia: Mar 30
- Latest typical last frostPittsburgh: Apr 24
- Most muggy daysPhiladelphia: 52 a year
- Fewest muggy daysPittsburgh: 30 a year
All Pennsylvania cities
| City | Jan high | Jul high | Wet days/yr | Snow/yr | Best months |
|---|---|---|---|---|---|
| Allentown | 38°F | 86°F | 129 | 33.1 in | May |
| Gettysburg | 38°F | 86°F | 123 | 27.0 in | May |
| Philadelphia | 41°F | 88°F | 121 | 23.1 in | May |
| Pittsburgh | 36°F | 83°F | 154 | 44.1 in | May, Sep |