Temperatures in September
It's warm in September in Philadelphia with an average temperature of 27°C. Temperatures this month range from a low of 22°C to a high of 31°C. At night, you can expect temperatures between 15°C and 21°C.
Max and Min Temperatures per Day
This chart shows the daily maximum and minimum temperatures in degrees Celsius for Philadelphia in September. The red line indicates the max temperatures, and the blue line shows the minimums.
Start of September
The month of September starts in Philadelphia with hot temperatures, averaging around 29°C during the day and nights close to 20°C. You can expect regular precipitation, but there’s also a chance for some sunny days in the first days of the month.
Since temperatures can differ between day and night, it’s a good idea to dress in layers.
Mid-September
By mid-September, the average daytime temperature drops to around 27°C, with nights close to 18°C. There might be a few showers during this period, but plenty of dry days with sunshine too.
Temperatures vary between day and night, so it’s smart to wear layers.
End of September
By the end of September, the average daytime temperature in Philadelphia will be around 25°C, with nights close to 16°C. There’s regular precipitation, but with a bit of luck, you’ll also get some dry and sunny days.
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Precipitation in September
In September, there is an average of 97 mm of precipitation, spread over 8 days. The wind speed is around 4 Bft, mostly coming from the South.
The average precipitation chance is 26% per day this month. Though it seems pretty low, the weather’s variable. Some days have higher and others lower precipitation chances, which lowers the average.
Precipitation Chance
This chart shows the daily precipitation chance (in percentages) in September for Philadelphia. 0% means it never rained on that day in the past 10 years, and 100% means it rained every day. All values in between represent the average chance of precipitation on that day.
Philadelphia in September |
London | ||
|---|---|---|---|
 Average Temperature |
27°C | 20°C | |
 High Temp |
31°C | 22°C | |
| Low Temp |
22°C | 17°C | |
 Total Precipitation |
97 mm | 44 mm | |
| Rainy Days |
8 days | 8 days | |
August
UV index
The UV index is a maximum of 6 this month. That's a moderate to high value on the intensity scale of 1 to 11. Unprotected skin can burn within 15-25 minutes.
Is September a good time to visit Philadelphia?
Want nice weather? Then September is a great time to be in Philadelphia. You’ll have pleasant temperatures and not too much rain this month.
Temperature records for Philadelphia in September
With 36°C, Philadelphia hit the highest temperature in the last 10 years in September 2023. The lowest daytime temperature in this month was 16°C in 2018. The extreme night temperatures ranged from a low of 7°C to a high of 27°C.
Check out the climate of Philadelphia for all months and discover the best travel time
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Daily Temperature in September in Philadelphia
This chart shows the average daily temperatures, both day and night, for each day in September in Philadelphia, measured in degrees Celsius. The red line represents the maximum temperatures, while the blue line shows the minimums. The days of the month are displayed at the bottom of the chart. The data, based on historical observations, gives an overview of the average daily temperatures during this month.
Daily Precipitation in September in Philadelphia
The chart below shows the average daily precipitation in September for Philadelphia, measured in millimetres over the past years. Precipitation is always measured as water, even if it’s snow or hail. The days of the month are shown at the bottom of the chart.
A low average precipitation means that the chance of rain on that day is usually small, while a higher average suggests that rain is more likely. But it’s still an average, so each day can be different. Based on historical weather data for September, you can expect around 8 days of rain in Philadelphia.
Daily UV Index in September in Philadelphia
This chart shows the average daily UV index in September in Philadelphia, with the UV index ranging from 0 to a maximum of 11. The bottom of the chart shows the days of the month. Based on historical data, this chart provides an idea of the daily UV radiation levels you can expect.
Temperature in September in Philadelphia Over the Years
This chart shows the average temperature in September in Philadelphia, measured in degrees Celsius, over the past years.
Total Precipitation in September in Philadelphia Over the Years
This chart shows the average precipitation in September in Philadelphia, measured in millimetres over the past years. Precipitation is always measured as water, even if it’s snow or hail.
Daily climate in September for Philadelphia
Click on a specific day in September for detailed info on the typical weather on that day in Philadelphia. Check out the historical temperatures and precipitation over the past 10 years on this day.
Weather experiences in September in Philadelphia
Have you been to Philadelphia in September?
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Average Weather in Philadelphia by Month
Click on a month below to see detailed weather info for Philadelphia. Based on historical weather data, you can see the average temperature, precipitation, wind, and UV index for each day of the month.
Or check out the climate of Philadelphia for all months at once
