Contents
- Weather in September
- Frequently asked questions
- Average temperature in September
- Average pressure in September
- Average wind speed in September
- Average humidity in September
- Average rainfall in September
- Average rainfall days in September
- Average snowfall in September
- Average snowfall days in September
- Average daylight in September
- Average sunshine in September
- Average sunshine days in September
- Average UV index in September
- Average cloud cover in September
- Average visibility in September
Weather in September
Temperature
In the transition to September, West Chester observes a minor drop in the average high-temperature, shifting from a moderately hot 82.4°F (28°C) in August to a still warm 75.7°F (24.3°C). West Chester experiences a mean temperature of 59.2°F (15.1°C) during September nights.Humidity
In September, the average relative humidity in West Chester, Pennsylvania, is 77%.Rainfall
In West Chester, in September, it is raining for 11.5 days, with typically 1.1" (28mm) of accumulated precipitation. In West Chester, during the entire year, the rain falls for 128.5 days and collects up to 14.92" (379mm) of precipitation.Snowfall
In West Chester, snow does not fall in June through October.Daylight
The average length of the day in September in West Chester is 12h and 26min.On the first day of September, sunrise is at 6:30 am and sunset at 7:33 pm. On the last day of the month, sunrise is at 6:58 am and sunset at 6:45 pm EDT.
Sunshine
In West Chester, the average sunshine in September is 8.6h.UV index
The average daily maximum UV index in September is 4. A UV Index estimate of 3 to 5 represents a moderate threat to health from unsafe exposure to UV radiation for the ordinary person.Note: A maximum daily UV index of 4 during September morphs into the following directions:
Undertake precautions - Guarding against sun damage is counselled. Stay safe from the Sun's strongest UV rays by limiting exposure during midday. In bright sunlight, prioritize sunglasses that grant protection from UVA and UVB radiation.
Frequently asked questions
What are the temperatures in West Chester in September?
What is the average humidity in September in West Chester?
How much does it rain in West Chester in September?
When it does not snow in West Chester?
What is the average length of the day in September in West Chester?
When is the sunrise / sunset in September in West Chester?
How long on average sun shines in September in West Chester?
How high is the UV index in September in West Chester?
Average temperature in September
West Chester, PA
- Average high temperature in September: 75.7°F
The warmest month (with the highest average high temperature) is July (84.9°F).
The month with the lowest average high temperature is January (36.5°F).
- Average low temperature in September: 59.2°F
The month with the highest average low temperature is July (67.1°F).
The coldest month (with the lowest average low temperature) is January (24.4°F).
Average pressure in September
West Chester, 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
West Chester, PA
- Average wind speed in September: 5.7mph
The windiest month (with the highest average wind speed) is March (8.6mph).
The calmest month (with the lowest average wind speed) is August (5.3mph).
Average humidity in September
West Chester, PA
- Average humidity in September: 77%
The months with the highest relative humidity are February and October (79%).
The month with the lowest relative humidity is April (73%).
Average rainfall in September
West Chester, PA
- Average rainfall in September: 1.1"
The wettest month (with the highest rainfall) is August (2.01").
The driest month (with the least rainfall) is January (0.83").
Average rainfall days in September
West Chester, PA
- Average rainfall days in September: 11.5 days
The month with the highest number of rainy days is July (15.3 days).
The month with the least rainy days is January (5.7 days).
Average snowfall in September
West Chester, PA
- Average snowfall in September: 0"
The month with the highest snowfall is March (1.54").
The months with the least snowfall are June, July, August, September and October (0").
Average snowfall days in September
West Chester, PA
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is January (5.5 days).
The months with the least snowfall days are June, July, August, September and October (0 days).
Average daylight in September /
Average sunshine in September
West Chester, PA
- Average daylight in September: 12h and 2min
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 4min
The month with the most sunshine is July (Average sunshine: 10h and 36min).
The month with the least sunshine is February (Average sunshine: 4h and 36min).
Average sunshine days in September
West Chester, PA
- Average sunshine days in September: 17 days
The month with the most sunshine days is November (21.7 days).
The month with the least sunshine days is August (13.1 days).
Average UV index in September
West Chester, 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
West Chester, PA
- Average cloud cover in September: 39
The month with the most cloud cover is February (Cloud cover 49).
The month with the least cloud cover is July (Cloud cover 32).
Average visibility in September
West Chester, 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).
West Chester, Pennsylvania, USA
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