Philadelphia Weather in August

The climate in Philadelphia during August can be summarized as hot, humid and a little damp.

August is in the summer in Philadelphia and is typically the 2nd warmest month of the year. Daytime maximum temperatures average around a steamy 33°C (91°F), whilst at night 20°C (68°F) is normal.

On average August is the 4th driest month of the year in Philadelphia with around 94mm 3.7 inches of rain making it a a little damp time to visit. This rainfall is typically spread over 9 days, although this may vary considerably.

On the flip side this corresponds to an average of 8.8 hours of sunshine per day.

The data used in these monthly averages covers a period of over 100 years right up until last year. As such they are a valid prediction of what to expect for the weather in Philadelphia in August 2025.