September weather forecastKnoxville, PA
September
Weather in September
The first month of the autumn, September, is still a pleasant month in Knoxville, Pennsylvania, with an average temperature varying between 69.8°F (21°C) and 49.5°F (9.7°C).Temperature
Knoxville's September weather features a light decline in high-temperatures, reducing from a moderately hot 76.6°F (24.8°C) in August to a pleasant 69.8°F (21°C). During September, the temperature tends to dip to an average of 49.5°F (9.7°C) at night.Humidity
In Knoxville, the average relative humidity in September is 81%.Rainfall
In Knoxville, in September, during 13.4 rainfall days, 2.13" (54mm) of precipitation is typically accumulated. In Knoxville, during the entire year, the rain falls for 168.3 days and collects up to 28.19" (716mm) of precipitation.Snowfall
June through September are months without snowfall.Daylight
The average length of the day in September is 12h and 28min.On the first day of September, sunrise is at 6:36 am and sunset at 7:42 pm. On the last day of the month, sunrise is at 7:06 am and sunset at 6:52 pm EDT.
Sunshine
In Knoxville, Pennsylvania, the average sunshine in September is 8.3h.UV index
The average daily maximum UV index in September is 3. A UV Index estimate of 3 to 5 represents a medium vulnerability from unsafe exposure to UV radiation for the average person.Note: The average daily UV index of 3 in September transforms into the following instructions:
Take precautions - Protection against sunburn is recommended. The Sun is most powerful around mid-day, so it's a good practice to reduce direct exposure. Employ a wide-brim hat for potent defense against up to 50% of UV rays.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in September
Knoxville, PA
- Average high temperature in September: 69.8°F
The warmest month (with the highest average high temperature) is July (79.2°F).
The month with the lowest average high temperature is January (28.2°F).
- Average low temperature in September: 49.5°F
The month with the highest average low temperature is July (57°F).
The coldest month (with the lowest average low temperature) is January (16.9°F).
Average pressure in September
Knoxville, PA
- Average pressure in September: 30.06"Hg
The month with the highest atmospheric pressure is November (30.11"Hg).
The month with the lowest atmospheric pressure is June (29.94"Hg).
Average wind speed in September
Knoxville, PA
- Average wind speed in September: 6.3mph
The windiest month (with the highest average wind speed) is January (9.6mph).
The calmest month (with the lowest average wind speed) is August (6mph).
Average humidity in September
Knoxville, PA
- Average humidity in September: 81%
The month with the highest relative humidity is February (86%).
The months with the lowest relative humidity are April, May and June (78%).
Average rainfall in September
Knoxville, PA
- Average rainfall in September: 2.13"
The wettest month (with the highest rainfall) is April (2.95").
The driest month (with the least rainfall) is November (1.81").
Average rainfall days in September
Knoxville, PA
- Average rainfall days in September: 13.4 days
The month with the highest number of rainy days is July (18.9 days).
The month with the least rainy days is February (7.2 days).
Average snowfall in September
Knoxville, PA
- Average snowfall in September: 0"
The month with the highest snowfall is February (7.76").
The months with the least snowfall are June, July, August and September (0").
Average snowfall days in September
Knoxville, PA
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is January (18.8 days).
The months with the least snowfall days are June, July, August and September (0 days).
Average daylight in September /
Average sunshine in September
Knoxville, PA
- Average daylight in September: 12h and 30min
The month with the longest days is June (Average daylight: 15h and 12min).
The month with the shortest days is December (Average daylight: 9h and 12min).
- Average sunshine in September: 8h and 18min
The month with the most sunshine is July (Average sunshine: 9h and 48min).
The months with the least sunshine are January, February and December (Average sunshine: 3h and 6min).
Average sunshine days in September
Knoxville, PA
- Average sunshine days in September: 14.9 days
The month with the most sunshine days is September (14.9 days).
The month with the least sunshine days is February (7.1 days).
Average UV index in September
Knoxville, PA
- Average UV index in September: 3
The months with the highest UV index are May, June, July and August (UV index 5).
The months with the lowest UV index are January and December (UV index 1).
Average cloud cover in September
Knoxville, PA
- Average cloud cover in September: 44
The month with the most cloud cover is January (Cloud cover 71).
The month with the least cloud cover is August (Cloud cover 39).
Average visibility in September
Knoxville, PA
- Average visibility in September: 5mi
The months with the highest visibility are January, February, March, April, May, June, July, August, September, October, November and December (5mi).
The months with the lowest visibility are January, February, March, April, May, June, July, August, September, October, November and December (5mi).
