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
The start of September involves a subtle temperature drop, shifting from a moderately hot 79.2°F (26.2°C) in August to a pleasant 72.1°F (22.3°C). During the month of September, the temperature in Williamsport generally drops to a low average of 51.4°F (10.8°C).Humidity
The average relative humidity in September is 81%.Rainfall
In Williamsport, during September, the rain falls for 11.2 days and regularly aggregates up to 1.38" (35mm) of precipitation. Throughout the year, in Williamsport, there are 145.2 rainfall days, and 16.57" (421mm) of precipitation is accumulated.Snowfall
May through September are months without snowfall.Daylight
The average length of the day in September is 12h and 28min.On the first day of the month, sunrise is at 6:35 am and sunset at 7:40 pm. On the last day of September, sunrise is at 7:04 am and sunset at 6:51 pm EDT.
Sunshine
The average sunshine in September is 8.6h.UV index
The average daily maximum UV index in September is 3. A UV Index of 3 to 5 symbolizes a moderate threat to health from exposure to the Sun's UV rays for ordinary individuals.Note: An average maximum UV index of 3 in September leads to these recommendations:
Take care. Persons with lighter skin might suffer burns in less than 30 minutes. Avoiding direct sun during mid-day hours can prevent harmful UV radiation exposure. For excellent sun protection for the eyes, ears, face, and neck, consider a wide-brim hat.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
What is the usual temperature for Williamsport in September?
What is the average humidity in September?
How much does it rain in September?
When it does not snow?
Does it snow in Williamsport in September?
How many hours of daylight does Williamsport have in September?
What time are sunrise and sunset in September?
How many hours of sunshine does Williamsport have in September?
What is the UV index reading in September?
Average temperature in September
Williamsport, PA
- Average high temperature in September: 72.1°F
The warmest month (with the highest average high temperature) is July (81.7°F).
The month with the lowest average high temperature is January (30.6°F).
- Average low temperature in September: 51.4°F
The month with the highest average low temperature is July (59.2°F).
The coldest month (with the lowest average low temperature) is January (18.9°F).
Average pressure in September
Williamsport, PA
- Average pressure in September: 30.07"Hg
The month with the highest atmospheric pressure is November (30.13"Hg).
The month with the lowest atmospheric pressure is June (29.94"Hg).
Average wind speed in September
Williamsport, PA
- Average wind speed in September: 5.3mph
The windiest months (with the highest average wind speed) are January, March and April (7.5mph).
The calmest month (with the lowest average wind speed) is August (4.8mph).
Average humidity in September
Williamsport, PA
- Average humidity in September: 81%
The month with the highest relative humidity is February (84%).
The months with the lowest relative humidity are April and July (77%).
Average rainfall in September
Williamsport, PA
- Average rainfall in September: 1.38"
The wettest month (with the highest rainfall) is April (1.93").
The driest month (with the least rainfall) is November (0.94").
Average rainfall days in September
Williamsport, PA
- Average rainfall days in September: 11.2 days
The month with the highest number of rainy days is May (16.6 days).
The month with the least rainy days is February (7.5 days).
Average snowfall in September
Williamsport, PA
- Average snowfall in September: 0"
The month with the highest snowfall is February (2.28").
The months with the least snowfall are May, June, July, August and September (0").
Average snowfall days in September
Williamsport, PA
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is January (11.8 days).
The months with the least snowfall days are June, July, August and September (0 days).
Average daylight in September /
Average sunshine in September
Williamsport, PA
- Average daylight in September: 12h and 3min
The month with the longest days is June (Average daylight: 15h and 6min).
The month with the shortest days is December (Average daylight: 9h and 18min).
- Average sunshine in September: 8h and 4min
The month with the most sunshine is July (Average sunshine: 10h and 6min).
The months with the least sunshine are January and February (Average sunshine: 3h and 42min).
Average sunshine days in September
Williamsport, PA
- Average sunshine days in September: 16.8 days
The month with the most sunshine days is November (18.7 days).
The month with the least sunshine days is May (11.8 days).
Average UV index in September
Williamsport, PA
- Average UV index in September: 3
The month with the highest UV index is July (UV index 6).
The months with the lowest UV index are January, February, March, October, November and December (UV index 2).
Average cloud cover in September
Williamsport, PA
- Average cloud cover in September: 41
The months with the most cloud cover are January and February (Cloud cover 60).
The month with the least cloud cover is July (Cloud cover 35).
Average visibility in September
Williamsport, PA
- Average visibility in September: 4mi
The month with the highest visibility is April (6mi).
The month with the lowest visibility is September (4mi).
Williamsport, Pennsylvania, USA
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