Contents
- Weather in September
- Frequently asked questions
- Average temperature in September
- Average pressure in September
- Average wind speed in September
- Average humidity in September
- Average rainfall in September
- Average rainfall days in September
- Average snowfall in September
- Average snowfall days in September
- Average daylight in September
- Average sunshine in September
- Average sunshine days in September
- Average UV index in September
- Average cloud cover in September
- Average visibility in September
Weather in September
Temperature
The onset of September is marked by a minor decrease in temperature, transitioning from a moderately hot 80.8°F (27.1°C) in August to a still warm 75.4°F (24.1°C). Illinois City's average low-temperature during September nights is observed to be a mild 56.3°F (13.5°C).Humidity
In Illinois City, Illinois, the average relative humidity in September is 76%.Rainfall
In Illinois City, in September, it is raining for 9.5 days, with typically 1.38" (35mm) of accumulated precipitation. In Illinois City, during the entire year, the rain falls for 128 days and collects up to 19.29" (490mm) of precipitation.Snowfall
May through September are months without snowfall in Illinois City.Daylight
In Illinois City, the average length of the day in September is 12h and 28min.On the first day of the month, sunrise is at 6:30 am and sunset at 7:36 pm. On the last day of September, sunrise is at 7:00 am and sunset at 6:46 pm CDT.
Sunshine
In Illinois City, the average sunshine in September is 9.4h.UV index
The average daily maximum UV index in September in Illinois City is 4. A UV Index value of 3 to 5 symbolizes a medium vulnerability from unprotected exposure to Sun's UV rays for average individuals.Note: A daily high UV index of 4 in September leads to these guidelines:
Ensure safety - Recommendations to avert sunburn are presented. Solar radiation peaks around mid-day, so it's wise to limit exposure to the Sun at this time. To mitigate harm from sun exposure, pick sunglasses offering UVA and UVB defense.
Frequently asked questions
What is the usual temperature for Illinois City in September?
What is the average humidity in September in Illinois City?
How much does it rain in Illinois City in September?
When it does not snow in Illinois City?
Does it snow in Illinois City in September?
How many hours of daylight does Illinois City have in September?
When are sunrise and sunset in September in Illinois City?
How many hours of sunshine does Illinois City have in September?
What is the UV index reading in September in Illinois City?
Average temperature in September
Illinois City, IL
- Average high temperature in September: 75.4°F
The warmest month (with the highest average high temperature) is July (81.7°F).
The month with the lowest average high temperature is January (28.2°F).
- Average low temperature in September: 56.3°F
The month with the highest average low temperature is July (65.1°F).
The coldest month (with the lowest average low temperature) is January (16.2°F).
Average pressure in September
Illinois City, IL
- Average pressure in September: 30.02"Hg
The month with the highest atmospheric pressure is January (30.14"Hg).
The month with the lowest atmospheric pressure is June (29.9"Hg).
Average wind speed in September
Illinois City, IL
- Average wind speed in September: 7.8mph
The windiest month (with the highest average wind speed) is April (10.6mph).
The calmest month (with the lowest average wind speed) is August (6.7mph).
Average humidity in September
Illinois City, IL
- Average humidity in September: 76%
The months with the highest relative humidity are January and July (83%).
The month with the lowest relative humidity is October (71%).
Average rainfall in September
Illinois City, IL
- Average rainfall in September: 1.38"
The wettest month (with the highest rainfall) is May (3.31").
The driest month (with the least rainfall) is December (0.75").
Average rainfall days in September
Illinois City, IL
- Average rainfall days in September: 9.5 days
The month with the highest number of rainy days is June (17 days).
The month with the least rainy days is January (4.2 days).
Average snowfall in September
Illinois City, IL
- Average snowfall in September: 0"
The month with the highest snowfall is February (2.52").
The months with the least snowfall are May, June, July, August and September (0").
Average snowfall days in September
Illinois City, IL
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is January (10.3 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
Illinois City, IL
- Average daylight in September: 12h and 3min
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 12min).
- Average sunshine in September: 9h and 2min
The month with the most sunshine is July (Average sunshine: 10h and 18min).
The month with the least sunshine is January (Average sunshine: 4h and 0min).
Average sunshine days in September
Illinois City, IL
- Average sunshine days in September: 18.5 days
The month with the most sunshine days is November (19.6 days).
The month with the least sunshine days is June (10.8 days).
Average UV index in September
Illinois City, IL
- Average UV index in September: 4
The months with the highest UV index are June and July (UV index 6).
The month with the lowest UV index is January (UV index 1).
Average cloud cover in September
Illinois City, IL
- Average cloud cover in September: 30
The month with the most cloud cover is January (Cloud cover 57).
The month with the least cloud cover is August (Cloud cover 29).
Average visibility in September
Illinois City, 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).
Illinois City, Illinois, USA
Weather forecast for your location
2. Allow the app to use your location
