Belleville Average Rainfall by Month

This page shows the average precipitation (including snowfall) in each month of the year in Belleville, Illinois. It is based on NOAA data for the years 1991–2020.
What's the Rainiest Month in Belleville?
In Belleville, May has the greatest precipitation of any month. On average, Belleville gets 5.0 inches of precipitation in May.
May is also the month where rain is most common. 37.2% of days in May will have at least some rain.
What's the Driest Month in Belleville?
In Belleville, February has the least precipitation of any month. On average, Belleville gets 2.15 inches of precipitation in February.
September is the month with the lowest chance of precipitation. 21.9% of days in September will have measurable rain.
Month Precipitation % Chance
January 2.50 in 22.8
February 2.15 in 25.9
March 3.37 in 30.8
April 4.90 in 34.3
May 5.05 in 37.2
June 4.62 in 28.9
July 4.03 in 24.0
August 3.91 in 23.1
September 3.37 in 21.9
October 3.12 in 27.1
November 3.48 in 25.6
December 2.58 in 24.7
Year 42.91 in 27.2
Weather Station Details
Years Station Coordinates
1948–2024 Belleville SIU Research location