September weather forecastDonovan, IL
September
Weather in September
The first month of the autumn, September, is also a moderately hot month in Donovan, Illinois, with temperature in the range of an average high of 75.2°F (24°C) and an average low of 57°F (13.9°C).Temperature
The commencement of September introduces an average high-temperature of a still moderately hot 75.2°F (24°C), closely mirroring the preceding month. In Donovan, the expected average low-temperature for September is a refreshing 57°F (13.9°C).Humidity
The average relative humidity in September is 78%.Rainfall
In September, the rain falls for 10.7 days. Throughout September, 1.18" (30mm) of precipitation is accumulated. Throughout the year, there are 136.7 rainfall days, and 19.72" (501mm) of precipitation is accumulated.Snowfall
May through October 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 6:18 am and sunset at 7:22 pm. On the last day of September, sunrise is at 6:46 am and sunset at 6:33 pm CDT.
Sunshine
In September, the average sunshine is 8.6h.UV index
The average daily maximum UV index in September is 5. A UV Index reading of 3 to 5 represents a moderate threat to health from unprotected exposure to Sun's UV rays for the average person.Note: In September, the maximum UV index of 5 suggests these recommendations:
Exercise prevention - Warding off sunburn is urged. The Sun's harshest UV rays are around midday; it's wise to seek shade and limit time outdoors. Sunglasses that guard against UVA and UVB rays are pivotal in minimizing sun-induced ocular damage.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in September
Donovan, IL
- Average high temperature in September: 75.2°F
The warmest month (with the highest average high temperature) is July (81°F).
The month with the lowest average high temperature is January (30.6°F).
- Average low temperature in September: 57°F
The month with the highest average low temperature is July (64.4°F).
The coldest month (with the lowest average low temperature) is January (18.7°F).
Average pressure in September
Donovan, IL
- Average pressure in September: 30.03"Hg
The month with the highest atmospheric pressure is January (30.13"Hg).
The month with the lowest atmospheric pressure is June (29.93"Hg).
Average wind speed in September
Donovan, IL
- Average wind speed in September: 7.2mph
The windiest month (with the highest average wind speed) is January (10.3mph).
The calmest month (with the lowest average wind speed) is August (6.2mph).
Average humidity in September
Donovan, IL
- Average humidity in September: 78%
The month with the highest relative humidity is July (85%).
The month with the lowest relative humidity is October (71%).
Average rainfall in September
Donovan, IL
- Average rainfall in September: 1.18"
The wettest month (with the highest rainfall) is May (2.83").
The driest month (with the least rainfall) is February (0.98").
Average rainfall days in September
Donovan, IL
- Average rainfall days in September: 10.7 days
The month with the highest number of rainy days is May (17.4 days).
The month with the least rainy days is January (6.2 days).
Average snowfall in September
Donovan, IL
- Average snowfall in September: 0"
The month with the highest snowfall is January (2.56").
The months with the least snowfall are May, June, July, August, September and October (0").
Average snowfall days in September
Donovan, IL
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is January (10.5 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
Donovan, 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 36min
The month with the most sunshine is June (Average sunshine: 9h and 54min).
The month with the least sunshine is January (Average sunshine: 3h and 54min).
Average sunshine days in September
Donovan, IL
- Average sunshine days in September: 17 days
The month with the most sunshine days is November (19.6 days).
The month with the least sunshine days is July (10.1 days).
Average UV index in September
Donovan, 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
Donovan, IL
- Average cloud cover in September: 33
The month with the most cloud cover is January (Cloud cover 59).
The months with the least cloud cover are August and September (Cloud cover 33).
Average visibility in September
Donovan, IL
- Average visibility in September: 6mi
The months with the highest visibility are January, February, March, April, May, June, September, October, November and December (6mi).
The months with the lowest visibility are July and August (5mi).





