September weather forecastMount Union, PA
September
Weather in September
September, the first month of the autumn in Mount Union, is still a warm month, with an average temperature varying between 53.2°F (11.8°C) and 74.3°F (23.5°C).Temperature
The onset of September brings a small shift in high-temperatures, falling from a moderately hot 81.3°F (27.4°C) in August to a still warm 74.3°F (23.5°C). The average temperature during September nights dips to a cool 53.2°F (11.8°C).Humidity
In Mount Union, Pennsylvania, the average relative humidity in September is 79%.Rainfall
The month with the least rainfall is September, when the rain falls for 12.8 days and typically collects 1.85" (47mm) of precipitation.Snowfall
May through September are months without snowfall.Daylight
The average length of the day in September is 12h and 27min.On the first day of September, sunrise is at 6:39 am and sunset at 7:42 pm. On the last day of the month, sunrise is at 7:07 am and sunset at 6:54 pm EDT.
Sunshine
The average sunshine in September is 8.6h.UV index
In Mount Union, the average daily maximum UV index in September is 4. A UV Index estimate of 3 to 5 represents a moderate health risk from exposure to the Sun's UV radiation for average individuals.Note: The UV index of 4 in September translates into these instructions:
Put precautions into practice - Guidance to elude sunburn is provided. The best time to avoid the Sun's harmful UV radiation is during midday when it's most potent. Tightly woven clothing, when worn loosely, shields effectively against the Sun.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in September
Mount Union, PA
- Average high temperature in September: 74.3°F
The warmest month (with the highest average high temperature) is July (83.7°F).
The month with the lowest average high temperature is January (32.9°F).
- Average low temperature in September: 53.2°F
The month with the highest average low temperature is July (60.4°F).
The coldest month (with the lowest average low temperature) is January (20.1°F).
Average pressure in September
Mount Union, PA
- Average pressure in September: 30.06"Hg
The month with the highest atmospheric pressure is November (30.14"Hg).
The month with the lowest atmospheric pressure is June (29.95"Hg).
Average wind speed in September
Mount Union, PA
- Average wind speed in September: 4.8mph
The windiest month (with the highest average wind speed) is January (7.8mph).
The calmest month (with the lowest average wind speed) is August (4.3mph).
Average humidity in September
Mount Union, PA
- Average humidity in September: 79%
The month with the highest relative humidity is February (82%).
The month with the lowest relative humidity is July (75%).
Average rainfall in September
Mount Union, PA
- Average rainfall in September: 1.85"
The wettest month (with the highest rainfall) is May (3.07").
The driest month (with the least rainfall) is September (1.85").
Average rainfall days in September
Mount Union, PA
- Average rainfall days in September: 12.8 days
The month with the highest number of rainy days is May (17.7 days).
The month with the least rainy days is February (9.5 days).
Average snowfall in September
Mount Union, PA
- Average snowfall in September: 0"
The month with the highest snowfall is January (5.24").
The months with the least snowfall are May, June, July, August and September (0").
Average snowfall days in September
Mount Union, PA
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is January (12.2 days).
The months with the least snowfall days are May, June, July, August and September (0 days).
Average daylight in September /
Average sunshine in September
Mount Union, 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 18min).
- Average sunshine in September: 8h and 36min
The month with the most sunshine is July (Average sunshine: 10h and 18min).
The month with the least sunshine is January (Average sunshine: 4h and 12min).
Average sunshine days in September
Mount Union, PA
- Average sunshine days in September: 14.5 days
The month with the most sunshine days is November (16.7 days).
The month with the least sunshine days is May (10.7 days).
Average UV index in September
Mount Union, PA
- Average UV index in September: 4
The months with the highest UV index are May and June (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
Mount Union, PA
- Average cloud cover in September: 39
The month with the most cloud cover is January (Cloud cover 56).
The months with the least cloud cover are July and August (Cloud cover 34).
Average visibility in September
Mount Union, PA
- Average visibility in September: 5mi
The month with the highest visibility is April (6mi).
The months with the lowest visibility are January, February, March, May, June, July, August, September, October, November and December (5mi).





