Charleston Average Rainfall by Month

This page shows the average precipitation (including snowfall) in each month of the year in Charleston, Illinois. It is based on NOAA data for the years 1991–2020.

Average temperature by month

What's the Rainiest Month in Charleston?

In Charleston, April has the greatest precipitation of any month. On average, Charleston gets 5.0 inches of precipitation in April.

However, May is the month with the greatest chance of precipitation. 41.5% of days in May will have at least some rain.

What's the Driest Month in Charleston?

In Charleston, February has the least precipitation of any month. On average, Charleston gets 2.44 inches of precipitation in February.

August is the month with the lowest chance of precipitation. 25.9% of days in August will have measurable rain.

Month	Precipitation	% Chance
January	2.91 in	32.8
February	2.44 in	29.8
March	3.01 in	33.7
April	4.97 in	40.4
May	4.46 in	41.5
June	4.64 in	34.1
July	4.27 in	29.5
August	2.79 in	25.9
September	3.15 in	26.6
October	3.81 in	29.3
November	4.01 in	34.7
December	2.78 in	33.4
Year	43.69 in	32.8

Weather Station Details

Years	Station	Coordinates
1896–2024	Charleston	location