September weather forecastLower Allen, PA
September
Weather in September
September, the first month of the autumn in Lower Allen, is also a moderately hot month, with an average temperature ranging between max 74.3°F (23.5°C) and min 55.8°F (13.2°C).Temperature
The beginning of September brings a minor change in the average high-temperature, shifting from 81.1°F (27.3°C) in August to a still warm 74.3°F (23.5°C). An average low-temperature of 55.8°F (13.2°C) is anticipated throughout the nights during September.Humidity
The average relative humidity in September is 78%.Rainfall
The months with the least rainfall are January and September Rain falls for 10.6 days and accumulates 1.3" (33mm) of rain.Snowfall
In Lower Allen, Pennsylvania, snow does not fall in May through October.Daylight
The average length of the day in September is 12h and 27min.On the first day of the month, sunrise is at 6:35 am and sunset at 7:38 pm. On the last day of September, sunrise is at 7:03 am and sunset at 6:51 pm EDT.
Sunshine
In September, the average sunshine is 9h.UV index
In September, the average daily maximum UV index is 4. A UV Index reading of 3 to 5 represents a moderate threat to health from unsafe exposure to UV radiation for the ordinary person.Note: The maximum UV index of 4 during September leads to these instructions:
Exercise prevention - Warding off sunburn is urged. Solar radiation peaks around mid-day, so it's wise to limit exposure to the Sun at this time. By wearing a generously brimmed hat, you can cut UV radiation exposure significantly.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in September
Lower Allen, 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 (35.2°F).
- Average low temperature in September: 55.8°F
The month with the highest average low temperature is July (64°F).
The coldest month (with the lowest average low temperature) is January (22.3°F).
Average pressure in September
Lower Allen, 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
Lower Allen, PA
- Average wind speed in September: 5.4mph
The windiest month (with the highest average wind speed) is March (8.4mph).
The calmest month (with the lowest average wind speed) is August (4.8mph).
Average humidity in September
Lower Allen, PA
- Average humidity in September: 78%
The months with the highest relative humidity are February and May (80%).
The month with the lowest relative humidity is April (75%).
Average rainfall in September
Lower Allen, PA
- Average rainfall in September: 1.3"
The wettest months (with the highest rainfall) are May and August (2.09").
The driest months (with the least rainfall) are January and September (1.3").
Average rainfall days in September
Lower Allen, PA
- Average rainfall days in September: 10.6 days
The month with the highest number of rainy days is May (17 days).
The month with the least rainy days is January (7.3 days).
Average snowfall in September
Lower Allen, PA
- Average snowfall in September: 0"
The month with the highest snowfall is January (2.4").
The months with the least snowfall are May, June, July, August, September and October (0").
Average snowfall days in September
Lower Allen, PA
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is January (7.1 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
Lower Allen, 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: 9h and 0min
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 30min).
Average sunshine days in September
Lower Allen, PA
- Average sunshine days in September: 16.7 days
The month with the most sunshine days is November (19.6 days).
The month with the least sunshine days is May (12 days).
Average UV index in September
Lower Allen, PA
- Average UV index in September: 4
The months with the highest UV index are May, June and July (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
Lower Allen, PA
- Average cloud cover in September: 37
The month with the most cloud cover is February (Cloud cover 50).
The month with the least cloud cover is July (Cloud cover 31).
Average visibility in September
Lower Allen, 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).
