Climate averages 1991–2020
Philadelphia weather
in August.
A hot, wet month: the 2nd warmest and the 7th driest of the year.
Long-term climate patterns, not a forecast for a particular trip.
August is a hot month in Philadelphia: daytime highs average 28.8°C and nights cool to about 19.9°C. By daytime temperature it is the 2nd warmest of the 12 months.
Expect about 95 mm of rain on roughly 10 days, which makes August a wet month (the 7th driest of the 12 months). Daylight, from sunrise to sunset, lasts about 13 h 45 min on an average August day.
The nearest other city in this atlas is Camden (5 km away). In August its highs average 28.7°C, about as warm as Philadelphia, with 95 mm of rain.
Among the 498 cities listed in the United States, Philadelphia ranks joint 291st of 498 for the warmest August highs and joint 358th of 498 for the driest August (rainfall, lowest first). The mean August high of those 498 cities is 29.9°C; Philadelphia is 1.1°C cooler than that mean.
From August to September, average highs fall by 3.8°C to 25.1°C, and monthly rainfall rises from 95 mm to 104 mm.
The annual picture
August in context
Monthly rainfall
Average total · mmAverages from hourly ERA5 reanalysis data. Actual weather varies from year to year. How these numbers are calculated
Every month, side by side
Philadelphia climate table
| Month | Average highHigh / low | Average low | Rainfall mm/month | Rain days ≥1 mm/day | Daylight hours/dayDaylight h/day |
|---|---|---|---|---|---|
| January | 4.5°C-3.3°C | -3.3°C | 82 | 9.3 | 9.710 h |
| February | 6.2°C-2.8°C | -2.8°C | 76 | 9.0 | 10.711 h |
| March | 10.7°C1.0°C | 1.0°C | 104 | 10.5 | 11.912 h |
| April | 17.2°C6.7°C | 6.7°C | 92 | 10.2 | 13.213 h |
| May | 22.4°C12.3°C | 12.3°C | 90 | 11.1 | 14.414 h |
| June | 27.3°C17.6°C | 17.6°C | 97 | 10.6 | 15.015 h |
| July | 29.9°C20.7°C | 20.7°C | 98 | 10.7 | 14.715 h |
| August, selected | 28.8°C19.9°C | 19.9°C | 95 | 10.2 | 13.714 h |
| September | 25.1°C16.3°C | 16.3°C | 104 | 9.2 | 12.512 h |
| October | 18.6°C10.0°C | 10.0°C | 91 | 8.1 | 11.211 h |
| November | 12.4°C4.2°C | 4.2°C | 74 | 7.8 | 10.010 h |
| December | 7.0°C-0.4°C | -0.4°C | 100 | 9.3 | 9.49 h |
Rainfall is the average of the 30 separate monthly totals. A rain day is a local calendar day with at least 1 mm of precipitation. Daylight is the calculated sunrise-to-sunset length, not measured sunshine.
Compare places
August in nearby cities
- Camden in AugustUnited States · 5 kmHigh 28.7°C · Low 19.9°C · 95 mm rain
- Cherry Hill in AugustUnited States · 11 kmHigh 28.5°C · Low 20.0°C · 95 mm rain
- Wilmington (Delaware), United States in AugustUnited States · 40 kmHigh 28.2°C · Low 19.9°C · 100 mm rain
- Trenton in AugustUnited States · 46 kmHigh 28.4°C · Low 19.3°C · 102 mm rain
- Bethlehem, United States in AugustUnited States · 77 kmHigh 28.0°C · Low 17.9°C · 93 mm rain
- Reading, United States in AugustUnited States · 78 kmHigh 28.7°C · Low 18.9°C · 85 mm rain
- Allentown in AugustUnited States · 78 kmHigh 28.1°C · Low 17.9°C · 93 mm rain
- Toms River in AugustUnited States · 82 kmHigh 27.9°C · Low 20.6°C · 114 mm rain
Read the numbers correctly
Climate, not a promise.
These patterns help compare months. They cannot tell you the weather on a specific day of your trip.
Sources, method and limitsHow these numbers are made (what the highs, lows and rain days mean, the sources and the model cell used for Philadelphia) is explained once on the Philadelphia year overview and on the Sources, method and limits page.