September weather forecastMount Clare, IL
September
Weather in September
The first month of the autumn, September, is still a warm month in Mount Clare, Illinois, with an average temperature varying between 77.9°F (25.5°C) and 59.4°F (15.2°C).Temperature
As August transitions into September, the average high-temperature rests at a still warm 77.9°F (25.5°C), maintaining a close resemblance to the previous month. The low-temperature averages to a moderate 59.4°F (15.2°C) during the nights of September.Humidity
In Mount Clare, the average relative humidity in September is 75%.Rainfall
In Mount Clare, in September, during 10.4 rainfall days, 0.83" (21mm) of precipitation is typically accumulated. In Mount Clare, during the entire year, the rain falls for 121.4 days and collects up to 14.72" (374mm) of precipitation.Snowfall
April through October are months without snowfall in Mount Clare.Daylight
In September, the average length of the day is 12h and 26min.On the first day of the month, sunrise is at 6:28 am and sunset at 7:29 pm. On the last day of September, sunrise is at 6:55 am and sunset at 6:43 pm CDT.
Sunshine
The average sunshine in September in Mount Clare is 9.3h.UV index
In Mount Clare, the average daily maximum UV index in September is 5. A UV Index value of 3 to 5 symbolizes a moderate health risk from unsafe exposure to UV radiation for average individuals.Note: The maximum UV index, 5 during September, leads to the following recommendations:
Safety measures are advised. Light-skinned individuals may experience burns in under half an hour. Being exposed to the midday Sun can have harmful effects due to strong UV radiation; always take precautions. Prioritize a wide-brim hat for comprehensive sun defense for your face, neck, eyes, and ears.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in September
Mount Clare, IL
- Average high temperature in September: 77.9°F
The warmest month (with the highest average high temperature) is July (84.2°F).
The month with the lowest average high temperature is January (35.6°F).
- Average low temperature in September: 59.4°F
The month with the highest average low temperature is July (67.5°F).
The coldest month (with the lowest average low temperature) is January (22.6°F).
Average pressure in September
Mount Clare, IL
- Average pressure in September: 30.02"Hg
The month with the highest atmospheric pressure is January (30.16"Hg).
The month with the lowest atmospheric pressure is June (29.92"Hg).
Average wind speed in September
Mount Clare, IL
- Average wind speed in September: 6.4mph
The windiest month (with the highest average wind speed) is January (10mph).
The calmest month (with the lowest average wind speed) is July (5.8mph).
Average humidity in September
Mount Clare, IL
- Average humidity in September: 75%
The month with the highest relative humidity is July (81%).
The month with the lowest relative humidity is October (71%).
Average rainfall in September
Mount Clare, IL
- Average rainfall in September: 0.83"
The wettest month (with the highest rainfall) is June (1.89").
The driest month (with the least rainfall) is February (0.67").
Average rainfall days in September
Mount Clare, IL
- Average rainfall days in September: 10.4 days
The month with the highest number of rainy days is July (14 days).
The month with the least rainy days is January (5.8 days).
Average snowfall in September
Mount Clare, IL
- Average snowfall in September: 0"
The month with the highest snowfall is December (0.98").
The months with the least snowfall are April, May, June, July, August, September and October (0").
Average snowfall days in September
Mount Clare, IL
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is January (6.3 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
Mount Clare, IL
- Average daylight in September: 12h and 24min
The month with the longest days is June (Average daylight: 14h and 54min).
The month with the shortest days is December (Average daylight: 9h and 30min).
- Average sunshine in September: 9h and 18min
The months with the most sunshine are June and July (Average sunshine: 10h and 18min).
The month with the least sunshine is January (Average sunshine: 4h and 24min).
Average sunshine days in September
Mount Clare, IL
- Average sunshine days in September: 17.2 days
The month with the most sunshine days is January (20.9 days).
The month with the least sunshine days is July (12.5 days).
Average UV index in September
Mount Clare, IL
- Average UV index in September: 5
The months with the highest UV index are June, July and August (UV index 6).
The months with the lowest UV index are January, February, November and December (UV index 2).
Average cloud cover in September
Mount Clare, IL
- Average cloud cover in September: 29
The month with the most cloud cover is January (Cloud cover 52).
The months with the least cloud cover are June, July, August and September (Cloud cover 29).
Average visibility in September
Mount Clare, IL
- Average visibility in September: 6mi
The months with the highest visibility are January, February, March, April, May, June, July, August, September, October, November and December (6mi).
The months with the lowest visibility are January, February, March, April, May, June, July, August, September, October, November and December (6mi).





