September weather forecastCollinsville, IL
September
Weather in September
The first month of the autumn, September, is still a warm month in Collinsville, Illinois, with an average temperature ranging between max 79°F (26.1°C) and min 59.9°F (15.5°C).Temperature
September's presence records an average high-temperature of a still warm 79°F (26.1°C), closely mirroring August's climate. An average low-temperature of 59.9°F (15.5°C) is noted during the month of September.Humidity
In Collinsville, the average relative humidity in September is 75%.Rainfall
In Collinsville, during September, the rain falls for 12.3 days and regularly aggregates up to 2.13" (54mm) of precipitation. In Collinsville, Illinois, during the entire year, the rain falls for 149.9 days and collects up to 33.94" (862mm) of precipitation.Snowfall
January through March, September, November and December are months with snowfall. September is the first month it typically snows. Throughout September, in the average 0.1 snowfall days, it receives 0.04" (1mm) of snow. In Collinsville, during the entire year, snow falls for 20.7 days and aggregates up to 7.13" (181mm) of snow.Daylight
In September, the average length of the day in Collinsville is 12h and 25min.On the first day of September, sunrise is at 6:29 am and sunset at 7:29 pm. On the last day of the month, sunrise is at 6:55 am and sunset at 6:43 pm CDT.
Sunshine
In September, the average sunshine in Collinsville is 9.3h.UV index
The average daily maximum UV index in September is 5. A UV Index of 3 to 5 symbolizes a moderate threat to health from unprotected exposure to Sun's UV rays for the ordinary person.Note: The average daily UV index of 5 in September transforms into the following instructions:
Exercise prevention - Warding off sunburn is urged. The best time to avoid the Sun's harmful UV radiation is during midday when it's most potent. Employ a wide-brim hat for potent defense against up to 50% of UV rays. Mark this! Snow reflection can nearly double the UV radiation intensity from the Sun.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in September
Collinsville, IL
- Average high temperature in September: 79°F
The warmest month (with the highest average high temperature) is July (85.6°F).
The month with the lowest average high temperature is January (37.4°F).
- Average low temperature in September: 59.9°F
The month with the highest average low temperature is July (68.2°F).
The coldest month (with the lowest average low temperature) is January (24.3°F).
Average pressure in September
Collinsville, 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
Collinsville, IL
- Average wind speed in September: 6.2mph
The windiest month (with the highest average wind speed) is January (9.5mph).
The calmest month (with the lowest average wind speed) is July (5.6mph).
Average humidity in September
Collinsville, IL
- Average humidity in September: 75%
The months with the highest relative humidity are May, July and August (79%).
The month with the lowest relative humidity is October (71%).
Average rainfall in September
Collinsville, IL
- Average rainfall in September: 2.13"
The wettest month (with the highest rainfall) is May (4.17").
The driest month (with the least rainfall) is February (1.77").
Average rainfall days in September
Collinsville, IL
- Average rainfall days in September: 12.3 days
The month with the highest number of rainy days is May (17.1 days).
The month with the least rainy days is January (7.8 days).
Average snowfall in September
Collinsville, IL
- Average snowfall in September: 0.04"
The month with the highest snowfall is January (2.13").
The months with the least snowfall are April, May, June, July, August and October (0").
Average snowfall days in September
Collinsville, IL
- Average snowfall days in September: 0.1 days
The month with the highest number of snowfall days is January (7 days).
The months with the least snowfall days are May, June, July and August (0 days).
Average daylight in September /
Average sunshine in September
Collinsville, IL
- Average daylight in September: 12h and 24min
The month with the longest days is June (Average daylight: 14h and 48min).
The month with the shortest days is December (Average daylight: 9h and 30min).
- Average sunshine in September: 9h and 18min
The month with the most sunshine is June (Average sunshine: 10h and 30min).
The month with the least sunshine is January (Average sunshine: 4h and 30min).
Average sunshine days in September
Collinsville, IL
- Average sunshine days in September: 15.1 days
The month with the most sunshine days is December (18.6 days).
The month with the least sunshine days is May (11.6 days).
Average UV index in September
Collinsville, IL
- Average UV index in September: 5
The months with the highest UV index are May, 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
Collinsville, IL
- Average cloud cover in September: 29
The month with the most cloud cover is January (Cloud cover 51).
The months with the least cloud cover are June and August (Cloud cover 28).
Average visibility in September
Collinsville, 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).
