September weather forecastBelleville, IL
September
Weather in September
September brings a nuanced change to Belleville's weather. As summer waves a warm goodbye, September gently escorts the city into the embrace of fall. The drop in temperatures becomes apparent, with the average high temperature comfortably resting at 79.3°F (26.3°C). Belleville fingers the edges of summer while also ushering in a beautiful fall season filled with color and tranquility. Displaying a unique blend of summer warmth and autumn coolness, September stands as a transitional treasure in Belleville's weather calendar.Temperature
The arrival of September records an average high-temperature of a still moderately hot 79.3°F (26.3°C), closely related to the 84.6°F (29.2°C) observed in August. In the month of September, the average low-temperature usually rests at a moderate 59.9°F (15.5°C).Humidity
In Belleville, the average relative humidity in September is 75%.Rainfall
In September, the rain falls for 12.5 days. Throughout September, 2.2" (56mm) of precipitation is accumulated. Throughout the year, there are 147.1 rainfall days, and 35.43" (900mm) of precipitation is accumulated.Snowfall
April through October are months without snowfall.Daylight
In September, the average length of the day 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 is 9.2h.UV index
In September, the average daily maximum UV index is 5. A UV Index estimate of 3 to 5 represents a medium vulnerability from exposure to the Sun's UV rays for ordinary individuals.Note: An average UV index of 5 in September transforms into this advice:
Take necessary precautions - Suggestions to elude sunburn are provided. Avoiding the Sun during its peak radiation time around midday is a healthy practice. Employ a hat with a wide brim for robust protection, cutting UV exposure by half. Be informed! The Sun's UV radiation can be nearly doubled due to the reflection from snow.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in September
Belleville, IL
- Average high temperature in September: 79.3°F
The warmest month (with the highest average high temperature) is July (85.8°F).
The month with the lowest average high temperature is January (37.8°F).
- Average low temperature in September: 59.9°F
The month with the highest average low temperature is July (68.4°F).
The coldest month (with the lowest average low temperature) is January (24.8°F).
Average pressure in September
Belleville, 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
Belleville, IL
- Average wind speed in September: 6.1mph
The windiest month (with the highest average wind speed) is January (9.4mph).
The calmest month (with the lowest average wind speed) is July (5.6mph).
Average humidity in September
Belleville, IL
- Average humidity in September: 75%
The months with the highest relative humidity are May and July (79%).
The month with the lowest relative humidity is October (71%).
Average rainfall in September
Belleville, IL
- Average rainfall in September: 2.2"
The wettest month (with the highest rainfall) is May (4.37").
The driest month (with the least rainfall) is February (1.93").
Average rainfall days in September
Belleville, IL
- Average rainfall days in September: 12.5 days
The month with the highest number of rainy days is May (16.4 days).
The month with the least rainy days is January (6.8 days).
Average snowfall in September
Belleville, IL
- Average snowfall in September: 0"
The month with the highest snowfall is January (2.4").
The months with the least snowfall are April, May, June, July, August, September and October (0").
Average snowfall days in September
Belleville, IL
- Average snowfall days in September: 0.1 days
The month with the highest number of snowfall days is January (7.3 days).
The months with the least snowfall days are May, June, July and August (0 days).
Average daylight in September /
Average sunshine in September
Belleville, 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 12min
The month with the most sunshine is June (Average sunshine: 10h and 18min).
The month with the least sunshine is January (Average sunshine: 4h and 30min).
Average sunshine days in September
Belleville, IL
- Average sunshine days in September: 16.1 days
The month with the most sunshine days is October (18.3 days).
The month with the least sunshine days is May (12.3 days).
Average UV index in September
Belleville, 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 and December (UV index 2).
Average cloud cover in September
Belleville, IL
- Average cloud cover in September: 31
The month with the most cloud cover is January (Cloud cover 52).
The month with the least cloud cover is June (Cloud cover 29).
Average visibility in September
Belleville, 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).
