September weather forecastWilmington, IL
September
Weather in September
September, the first month of the autumn in Wilmington, is still a warm month, with an average temperature varying between 56.8°F (13.8°C) and 74.8°F (23.8°C).Temperature
The commencement of September introduces an average high-temperature of a still moderately hot 74.8°F (23.8°C), closely mirroring the preceding month. Wilmington throughout September, records an average low-temperature of 56.8°F (13.8°C).Humidity
In September, the average relative humidity is 77%.Rainfall
In Wilmington, during September, the rain falls for 13.2 days and regularly aggregates up to 2.52" (64mm) of precipitation. In Wilmington, during the entire year, the rain falls for 160.4 days and collects up to 33.5" (851mm) of precipitation.Snowfall
In Wilmington, snow does not fall in May through September.Daylight
In Wilmington, the average length of the day in September is 12h and 28min.On the first day of September, sunrise is at 6:19 am and sunset at 7:24 pm. On the last day of the month, sunrise is at 6:49 am and sunset at 6:35 pm CDT.
Sunshine
The average sunshine in September is 8.7h.UV index
The average daily maximum UV index in September is 5. A UV Index estimate of 3 to 5 represents a moderate health risk from exposure to the Sun's UV rays for ordinary individuals.Note: A daily high UV index of 5 in September leads to these guidelines:
Be mindful. Individuals with a lighter skin tone may suffer burns in less than 30 minutes. The Sun's UV radiation is especially harmful around midday, so reduce exposure and stay safe. A hat with a broad brim is indispensable, filtering out up to half of UV rays.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in September
Wilmington, IL
- Average high temperature in September: 74.8°F
The warmest month (with the highest average high temperature) is July (81.1°F).
The month with the lowest average high temperature is January (29.7°F).
- Average low temperature in September: 56.8°F
The month with the highest average low temperature is July (64.6°F).
The coldest month (with the lowest average low temperature) is January (17.8°F).
Average pressure in September
Wilmington, IL
- Average pressure in September: 30.03"Hg
The month with the highest atmospheric pressure is January (30.12"Hg).
The month with the lowest atmospheric pressure is June (29.92"Hg).
Average wind speed in September
Wilmington, IL
- Average wind speed in September: 7mph
The windiest months (with the highest average wind speed) are January and April (9.9mph).
The calmest month (with the lowest average wind speed) is August (6mph).
Average humidity in September
Wilmington, IL
- Average humidity in September: 77%
The month with the highest relative humidity is July (84%).
The month with the lowest relative humidity is October (72%).
Average rainfall in September
Wilmington, IL
- Average rainfall in September: 2.52"
The wettest month (with the highest rainfall) is May (4.57").
The driest months (with the least rainfall) are February and November (1.69").
Average rainfall days in September
Wilmington, IL
- Average rainfall days in September: 13.2 days
The month with the highest number of rainy days is May (19.2 days).
The month with the least rainy days is January (5.8 days).
Average snowfall in September
Wilmington, IL
- Average snowfall in September: 0"
The month with the highest snowfall is February (4.29").
The months with the least snowfall are May, June, July, August and September (0").
Average snowfall days in September
Wilmington, IL
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is January (10.6 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
Wilmington, IL
- Average daylight in September: 12h and 30min
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 42min
The months with the most sunshine are June, July and August (Average sunshine: 9h and 48min).
The month with the least sunshine is January (Average sunshine: 3h and 54min).
Average sunshine days in September
Wilmington, IL
- Average sunshine days in September: 14 days
The month with the most sunshine days is November (17.2 days).
The month with the least sunshine days is July (8.6 days).
Average UV index in September
Wilmington, IL
- Average UV index in September: 5
The months with the highest UV index are June and July (UV index 6).
The month with the lowest UV index is December (UV index 1).
Average cloud cover in September
Wilmington, IL
- Average cloud cover in September: 33
The month with the most cloud cover is January (Cloud cover 60).
The months with the least cloud cover are August and September (Cloud cover 33).
Average visibility in September
Wilmington, IL
- Average visibility in September: 6mi
The months with the highest visibility are January, March, April, May, June, September, October, November and December (6mi).
The months with the lowest visibility are February, July and August (5mi).
