Philadelphia weather in September (Pennsylvania, United States of America)

This month is known as a warm month. The average maximum daytime temperature in Philadelphia in September lies at 26.0°C (78.8°F). The average minimum temperature goes down to around 14.3°C (57.74°F) (often the minimum temperature is noted at night).

Rainfall during September is high with an average of 107mm (4.2 inchec). There are generally around 8 rainy days. If you enjoy blue skies and sunshine, then this is a great time to go to Philadelphia with 218 hours of sun during the entire month.


Philadelphia, monthly averages in September

Show in Celsius
Min Temperature 57 °F  
Max Temperature 78 °F  
Water Temperature 71 °F *  
Chance of Rain 30%  
Precipitation 4 in  
Rainy days 9 days  
Humidity 72% *  
Sunshine 218 hrs *  
Percentage Sunshine 59% *  

Where to stay in Philadelphia

Where to go in the United States of America in September

Find out more about the weather in the United States of America in September and which places have the best weather conditions in this month.

Legend perfect weather pleasant tolerable unpleasant poor
Perfect weather is subjective. On this map perfect weather has been defined with temperatures between 20-29ºC / 68-84ºF and not too much precipitation (less than 90mm / 3.5inches a month).

So what to wear in September? Visitors traveling to Philadelphia should plan on bringing a totally waterproof coat since it will often be raining. However, also bring your summer cloths because it can be very warm or even hot. With a water temperature of around 22.0°C (71.6°F), this is a great month to swim so bring your swimwear.

What To Do

We rated the following activities from 1 (least suitable) to 10 (best) to do in September.

Outdoor sports

Interested in more climate information?

Weather and Climate provides you with all the information you need about the climate in Philadelphia.

Our site offers climate and forecast data for almost all countries in the world. Are you going to the United States of America? On this website you can find historical weather averages for many cities in the United States of America. Not sure yet where to go? We now have a tool which suggests which destination suits your ideal climate conditions. Find out where to go with our weather planner.