September weather forecastJoliett, PA
September
Weather in September
The first month of the autumn, September, is still a pleasant month in Joliett, Pennsylvania, with an average temperature varying between 54.1°F (12.3°C) and 73.2°F (22.9°C).Temperature
The beginning of September subtly marks a decrease in the average high-temperature, transitioning from a moderately hot 79.5°F (26.4°C) in August to an agreeable 73.2°F (22.9°C). An average nighttime temperature of 54.1°F (12.3°C) is recorded during September.Humidity
The average relative humidity in September is 80%.Rainfall
In Joliett, in September, it is raining for 9.6 days, with typically 0.87" (22mm) of accumulated precipitation. Throughout the year, there are 133.5 rainfall days, and 15.16" (385mm) of precipitation is accumulated.Snowfall
June through September are months without snowfall.Daylight
In September, the average length of the day is 12h and 27min.On the first day of the month, sunrise is at 6:33 am and sunset at 7:37 pm. On the last day of September, sunrise is at 7:02 am and sunset at 6:49 pm EDT.
Sunshine
In Joliett, the average sunshine in September is 8.6h.UV index
In September, the average daily maximum UV index is 4. A UV Index reading of 3 to 5 represents a moderate health risk from exposure to the Sun's UV radiation for ordinary individuals.Note: The maximum daily UV index, 4 in September, converts into the following recommendations:
Take precautions. Light skin individuals may get burned in less than 30 minutes. Around midday, solar radiation is most harmful; hence, exposure should be limited. On sunny days, it's ideal to wear sunglasses that filter out UVA and UVB rays.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in September
Joliett, PA
- Average high temperature in September: 73.2°F
The warmest month (with the highest average high temperature) is July (81.5°F).
The month with the lowest average high temperature is January (33.4°F).
- Average low temperature in September: 54.1°F
The month with the highest average low temperature is July (62.1°F).
The coldest month (with the lowest average low temperature) is January (20.7°F).
Average pressure in September
Joliett, PA
- Average pressure in September: 30.06"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
Joliett, PA
- Average wind speed in September: 5.5mph
The windiest month (with the highest average wind speed) is March (8.6mph).
The calmest month (with the lowest average wind speed) is August (4.8mph).
Average humidity in September
Joliett, PA
- Average humidity in September: 80%
The month with the highest relative humidity is February (82%).
The months with the lowest relative humidity are March and April (77%).
Average rainfall in September
Joliett, PA
- Average rainfall in September: 0.87"
The wettest month (with the highest rainfall) is August (1.93").
The driest month (with the least rainfall) is February (0.83").
Average rainfall days in September
Joliett, PA
- Average rainfall days in September: 9.6 days
The month with the highest number of rainy days is May (15.4 days).
The month with the least rainy days is January (6.8 days).
Average snowfall in September
Joliett, PA
- Average snowfall in September: 0"
The month with the highest snowfall is January (1.77").
The months with the least snowfall are June, July, August and September (0").
Average snowfall days in September
Joliett, PA
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is January (6.9 days).
The months with the least snowfall days are June, July, August and September (0 days).
Average daylight in September /
Average sunshine in September
Joliett, PA
- Average daylight in September: 12h and 30min
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 12min).
The month with the least sunshine is February (Average sunshine: 4h and 18min).
Average sunshine days in September
Joliett, PA
- Average sunshine days in September: 18.1 days
The month with the most sunshine days is January (20.8 days).
The month with the least sunshine days is May (12.7 days).
Average UV index in September
Joliett, PA
- Average UV index in September: 4
The months with the highest UV index are 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
Joliett, PA
- Average cloud cover in September: 39
The month with the most cloud cover is February (Cloud cover 54).
The month with the least cloud cover is July (Cloud cover 33).
Average visibility in September
Joliett, PA
- Average visibility in September: 5mi
The months with the highest visibility are January, March, April, June, November and December (6mi).
The months with the lowest visibility are February, May, July, August, September and October (5mi).





