Olney Average Rainfall by Month

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

Average temperature by month

What's the Rainiest Month in Olney?

In Olney, May has the greatest precipitation of any month. On average, Olney gets 5.6 inches of precipitation in May.

May is also the month where rain is most common. 40.9% of days in May will have at least some rain.

What's the Driest Month in Olney?

In Olney, February has the least precipitation of any month. On average, Olney gets 2.51 inches of precipitation in February.

September is the month with the lowest chance of precipitation. 25.6% of days in September will have measurable rain.

Month	Precipitation	% Chance
January	3.39 in	34.2
February	2.51 in	30.5
March	4.20 in	38.2
April	5.04 in	37.4
May	5.55 in	40.9
June	4.79 in	34.9
July	4.83 in	29.6
August	3.04 in	26.0
September	3.31 in	25.6
October	3.70 in	29.5
November	4.18 in	32.0
December	3.53 in	35.3
Year	47.75 in	33.1

Weather Station Details

Years	Station	Coordinates
1893–2024	Olney 2S	location