September weather forecastChesterbrook, PA
September
Weather in September
September, the first month of the autumn in Chesterbrook, is also a moderately hot month, with an average temperature fluctuating between 59.5°F (15.3°C) and 75.9°F (24.4°C).Temperature
The advent of September brings a slight shift in average high-temperature, moving from a moderately hot 82.9°F (28.3°C) in August to a still warm 75.9°F (24.4°C). In Chesterbrook, the nighttime temperature averages to a refreshing 59.5°F (15.3°C) during September.Humidity
The average relative humidity in September is 76%.Rainfall
In Chesterbrook, in September, during 11.9 rainfall days, 1.34" (34mm) of precipitation is typically accumulated. Throughout the year, there are 138.1 rainfall days, and 20.79" (528mm) of precipitation is accumulated.Snowfall
In Chesterbrook, snow does not fall in June through September.Daylight
In September, the average length of the day is 12h and 26min.On the first day of September, sunrise is at 6:30 am and sunset at 7:32 pm. On the last day of the month, sunrise is at 6:57 am and sunset at 6:45 pm EDT.
Sunshine
The average sunshine in September is 8.5h.UV index
In September, the average daily maximum UV index is 4. A UV Index of 3 to 5 symbolizes a moderate threat to health from exposure to the Sun's UV rays for the average person.Note: The average daily UV index of 4 in September transforms into the following instructions:
Exercise caution. The susceptibility of light skin individuals to burns is less than 30 minutes. The Sun is at its harshest during midday; protect yourself by staying in shaded areas and minimizing exposure. For a sun-safe wardrobe, go for clothes that are tightly woven and generously sized.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in September
Chesterbrook, PA
- Average high temperature in September: 75.9°F
The warmest month (with the highest average high temperature) is July (85.3°F).
The month with the lowest average high temperature is January (36.5°F).
- Average low temperature in September: 59.5°F
The month with the highest average low temperature is July (67.6°F).
The coldest month (with the lowest average low temperature) is January (24.3°F).
Average pressure in September
Chesterbrook, PA
- Average pressure in September: 30.06"Hg
The month with the highest atmospheric pressure is November (30.12"Hg).
The month with the lowest atmospheric pressure is June (29.94"Hg).
Average wind speed in September
Chesterbrook, PA
- Average wind speed in September: 5.7mph
The windiest month (with the highest average wind speed) is March (8.4mph).
The calmest month (with the lowest average wind speed) is August (5.3mph).
Average humidity in September
Chesterbrook, PA
- Average humidity in September: 76%
The months with the highest relative humidity are February and October (79%).
The months with the lowest relative humidity are April, July and August (73%).
Average rainfall in September
Chesterbrook, PA
- Average rainfall in September: 1.34"
The wettest month (with the highest rainfall) is August (2.72").
The driest months (with the least rainfall) are January, February and November (1.3").
Average rainfall days in September
Chesterbrook, PA
- Average rainfall days in September: 11.9 days
The month with the highest number of rainy days is July (16.8 days).
The month with the least rainy days is January (6.3 days).
Average snowfall in September
Chesterbrook, PA
- Average snowfall in September: 0"
The month with the highest snowfall is March (1.93").
The months with the least snowfall are June, July, August and September (0").
Average snowfall days in September
Chesterbrook, PA
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is January (6.1 days).
The months with the least snowfall days are June, July, August and September (0 days).
Average daylight in September /
Average sunshine in September
Chesterbrook, PA
- Average daylight in September: 12h and 24min
The month with the longest days is June (Average daylight: 15h and 0min).
The month with the shortest days is December (Average daylight: 9h and 24min).
- Average sunshine in September: 8h and 30min
The month with the most sunshine is July (Average sunshine: 10h and 30min).
The month with the least sunshine is February (Average sunshine: 4h and 30min).
Average sunshine days in September
Chesterbrook, PA
- Average sunshine days in September: 16.4 days
The month with the most sunshine days is November (20.1 days).
The month with the least sunshine days is July (12.7 days).
Average UV index in September
Chesterbrook, PA
- Average UV index in September: 4
The months with the highest UV index are May, June, July and August (UV index 6).
The months with the lowest UV index are January, February, March, November and December (UV index 2).
Average cloud cover in September
Chesterbrook, PA
- Average cloud cover in September: 41
The month with the most cloud cover is February (Cloud cover 50).
The month with the least cloud cover is July (Cloud cover 33).
Average visibility in September
Chesterbrook, PA
- Average visibility in September: 5mi
The months with the highest visibility are January, February, March, April, June, July, August, October, November and December (6mi).
The months with the lowest visibility are May and September (5mi).





