September weather forecastCentralia, IL
September
Weather in September
September, the first month of the autumn in Centralia, is also a moderately hot month, with an average temperature varying between 59.9°F (15.5°C) and 78.4°F (25.8°C).Temperature
September is characterized by a slight reduction in average high-temperature, easing from 83.8°F (28.8°C) in August to a still warm 78.4°F (25.8°C). Throughout September, the nighttime temperature in Centralia, Illinois, averages to a mild 59.9°F (15.5°C).Humidity
In September, the average relative humidity is 75%.Rainfall
The month with the least rainfall in Centralia, Illinois, is September, when the rain falls for 6.3 days and typically collects 0.24" (6mm) of precipitation.Snowfall
April through October are months without snowfall.Daylight
The average length of the day in September in Centralia is 12h and 25min.On the first day of September in Centralia, sunrise is at 6:26 am and sunset at 7:26 pm. On the last day of the month, sunrise is at 6:52 am and sunset at 6:40 pm CDT.
Sunshine
The average sunshine in September in Centralia is 9.1h.UV index
In September, the average daily maximum UV index in Centralia, Illinois, 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: The maximum daily UV index of 5 in September converts into the following recommendations:
Undertake protective steps - Recommendations to avoid sunburn are issued. Considering the strength of solar radiation at midday, one should avoid direct Sun exposure. Combat UV radiation's detrimental effects with sun-safe clothing and UV-blocking eyewear.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in September
Centralia, IL
- Average high temperature in September: 78.4°F
The warmest month (with the highest average high temperature) is July (84.9°F).
The month with the lowest average high temperature is January (37.2°F).
- Average low temperature in September: 59.9°F
The month with the highest average low temperature is July (67.6°F).
The coldest month (with the lowest average low temperature) is January (24.3°F).
Average pressure in September
Centralia, IL
- Average pressure in September: 30.03"Hg
The month with the highest atmospheric pressure is January (30.16"Hg).
The month with the lowest atmospheric pressure is June (29.93"Hg).
Average wind speed in September
Centralia, IL
- Average wind speed in September: 6.5mph
The windiest month (with the highest average wind speed) is February (10mph).
The calmest month (with the lowest average wind speed) is July (5.8mph).
Average humidity in September
Centralia, IL
- Average humidity in September: 75%
The months with the highest relative humidity are May and July (80%).
The month with the lowest relative humidity is October (71%).
Average rainfall in September
Centralia, IL
- Average rainfall in September: 0.24"
The wettest months (with the highest rainfall) are April and July (0.75").
The driest month (with the least rainfall) is September (0.24").
Average rainfall days in September
Centralia, IL
- Average rainfall days in September: 6.3 days
The month with the highest number of rainy days is May (10.1 days).
The month with the least rainy days is January (3.7 days).
Average snowfall in September
Centralia, IL
- Average snowfall in September: 0"
The month with the highest snowfall is January (0.28").
The months with the least snowfall are April, May, June, July, August, September and October (0").
Average snowfall days in September
Centralia, IL
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is January (3.8 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
Centralia, 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 6min
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
Centralia, IL
- Average sunshine days in September: 21.4 days
The months with the most sunshine days are January and December (24.5 days).
The month with the least sunshine days is May (16.8 days).
Average UV index in September
Centralia, 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, November and December (UV index 2).
Average cloud cover in September
Centralia, IL
- Average cloud cover in September: 30
The months with the most cloud cover are January and February (Cloud cover 51).
The month with the least cloud cover is June (Cloud cover 28).
Average visibility in September
Centralia, 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).





