September weather forecastRandolph, IL
September
Weather in September
September, the first month of the autumn in Randolph, is also a moderately hot month, with an average temperature varying between 57.7°F (14.3°C) and 75.9°F (24.4°C).Temperature
The transition from August to September brings an average high-temperature of a still moderately hot 75.9°F (24.4°C), barely different from August's 80.2°F (26.8°C). Throughout the nights in September, an average low-temperature of 57.7°F (14.3°C) is noted.Humidity
In September, the average relative humidity is 76%.Rainfall
In September, the rain falls for 10.3 days. Throughout September, 0.98" (25mm) of precipitation is accumulated. In Randolph, during the entire year, the rain falls for 124.4 days and collects up to 13.23" (336mm) of precipitation.Snowfall
May through October are months without snowfall.Daylight
In September, the average length of the day in Randolph is 12h and 27min.On the first day of the month, sunrise is at 6:24 am and sunset at 7:27 pm. On the last day of September, sunrise is at 6:52 am and sunset at 6:39 pm CDT.
Sunshine
In Randolph, the average sunshine in September is 9h.UV index
The average daily maximum UV index in September is 5. A UV Index estimate of 3 to 5 represents a moderate threat to health from exposure to the Sun's UV rays for average individuals.Note: In September, an average UV index of 5 transforms into the following instructions:
Guard yourself - Avoiding sunburn is suggested. The Sun's harshest UV rays are around midday; it's wise to seek shade and limit time outdoors. Sun-related eye harm can be minimized with proper sunglasses offering UVA and UVB coverage.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in September
Randolph, IL
- Average high temperature in September: 75.9°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 (31.3°F).
- Average low temperature in September: 57.7°F
The month with the highest average low temperature is July (64.9°F).
The coldest month (with the lowest average low temperature) is January (19.8°F).
Average pressure in September
Randolph, IL
- Average pressure in September: 30.03"Hg
The month with the highest atmospheric pressure is January (30.14"Hg).
The month with the lowest atmospheric pressure is June (29.92"Hg).
Average wind speed in September
Randolph, IL
- Average wind speed in September: 7.6mph
The windiest month (with the highest average wind speed) is January (10.9mph).
The calmest month (with the lowest average wind speed) is August (6.5mph).
Average humidity in September
Randolph, IL
- Average humidity in September: 76%
The month with the highest relative humidity is July (85%).
The month with the lowest relative humidity is October (71%).
Average rainfall in September
Randolph, IL
- Average rainfall in September: 0.98"
The wettest month (with the highest rainfall) is May (1.69").
The driest month (with the least rainfall) is December (0.67").
Average rainfall days in September
Randolph, IL
- Average rainfall days in September: 10.3 days
The month with the highest number of rainy days is May (15.8 days).
The month with the least rainy days is January (5.3 days).
Average snowfall in September
Randolph, IL
- Average snowfall in September: 0"
The month with the highest snowfall is January (1.61").
The months with the least snowfall are May, June, July, August, September and October (0").
Average snowfall days in September
Randolph, IL
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is January (8.5 days).
The months with the least snowfall days are May, June, July, August, September and October (0 days).
Average daylight in September /
Average sunshine in September
Randolph, IL
- Average daylight in September: 12h and 24min
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: 9h and 0min
The month with the most sunshine is June (Average sunshine: 10h and 6min).
The month with the least sunshine is January (Average sunshine: 3h and 54min).
Average sunshine days in September
Randolph, IL
- Average sunshine days in September: 17.3 days
The month with the most sunshine days is November (20.5 days).
The month with the least sunshine days is May (11.7 days).
Average UV index in September
Randolph, IL
- Average UV index in September: 5
The months with the highest UV index are June and July (UV index 6).
The months with the lowest UV index are January, February, November and December (UV index 2).
Average cloud cover in September
Randolph, IL
- Average cloud cover in September: 31
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 31).
Average visibility in September
Randolph, 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).





