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 arrival of September signals a subtle shift in temperature, down from a warm 79°F (26.1°C) in August to a pleasant 72.5°F (22.5°C). September nights observe an average temperature dip to a fresh 52.5°F (11.4°C).Humidity
In September, the average relative humidity is 80%.Rainfall
In Knox, during September, the rain falls for 13.9 days and regularly aggregates up to 1.97" (50mm) of precipitation. Throughout the year, there are 169.8 rainfall days, and 27.36" (695mm) of precipitation is accumulated.Snowfall
June through September are months without snowfall in Knox.Daylight
In September, the average length of the day is 12h and 28min.On the first day of September, sunrise is at 6:45 am and sunset at 7:50 pm. On the last day of the month, sunrise is at 7:14 am and sunset at 7:01 pm EDT.
Sunshine
In Knox, the average sunshine in September is 8.2h.UV index
In Knox, the average daily maximum UV index in September is 3. A UV Index reading of 3 to 5 represents a medium health hazard from unprotected exposure to Sun's UV rays for the ordinary person.Note: In September, the maximum UV index of 3 translates into these guidelines:
Exercise caution. The susceptibility of light skin individuals to burns is less than 30 minutes. Limiting exposure to the direct Sun during midday hours can help prevent harmful UV radiation effects. Always opt for UVA and UVB-resistant sunglasses on radiant days.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
What is the average September temperature?
What is the average humidity in September?
How much does it rain in September?
When it does not snow?
Does it snow in September?
How many hours of daylight does Knox have in September?
When are sunrise and sunset in September?
How long on average sun shines in September?
What is the UV index intensity in September?
Average temperature in September
Knox, PA
- Average high temperature in September: 72.5°F
The warmest month (with the highest average high temperature) is July (81°F).
The month with the lowest average high temperature is January (30.2°F).
- Average low temperature in September: 52.5°F
The month with the highest average low temperature is July (59°F).
The coldest month (with the lowest average low temperature) is January (17.8°F).
Average pressure in September
Knox, 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
Knox, PA
- Average wind speed in September: 5.7mph
The windiest month (with the highest average wind speed) is January (8.3mph).
The calmest month (with the lowest average wind speed) is August (5.2mph).
Average humidity in September
Knox, PA
- Average humidity in September: 80%
The months with the highest relative humidity are January and February (88%).
The month with the lowest relative humidity is July (78%).
Average rainfall in September
Knox, PA
- Average rainfall in September: 1.97"
The wettest month (with the highest rainfall) is April (3.15").
The driest month (with the least rainfall) is August (1.69").
Average rainfall days in September
Knox, PA
- Average rainfall days in September: 13.9 days
The month with the highest number of rainy days is May (19 days).
The month with the least rainy days is January (7.5 days).
Average snowfall in September
Knox, PA
- Average snowfall in September: 0"
The month with the highest snowfall is January (7.09").
The months with the least snowfall are June, July, August and September (0").
Average snowfall days in September
Knox, PA
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is January (21.3 days).
The months with the least snowfall days are June, July, August and September (0 days).
Average daylight in September /
Average sunshine in September
Knox, 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 1min
The month with the most sunshine is August (Average sunshine: 9h and 54min).
The month with the least sunshine is January (Average sunshine: 2h and 24min).
Average sunshine days in September
Knox, PA
- Average sunshine days in September: 14 days
The month with the most sunshine days is September (14 days).
The month with the least sunshine days is February (5.7 days).
Average UV index in September
Knox, PA
- Average UV index in September: 3
The months with the highest UV index are May, June, July and August (UV index 5).
The month with the lowest UV index is December (UV index 1).
Average cloud cover in September
Knox, PA
- Average cloud cover in September: 42
The month with the most cloud cover is January (Cloud cover 75).
The months with the least cloud cover are July and August (Cloud cover 38).
Average visibility in September
Knox, PA
- Average visibility in September: 5mi
The months with the highest visibility are March, April, May, June, July, August, September, October and November (5mi).
The months with the lowest visibility are January, February and December (4mi).
Knox, Pennsylvania, USA
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