St. Louis Average Rainfall by Month

This page shows the average precipitation (including snowfall) in each month of the year in St. Louis, Missouri. It is based on NOAA data for the years 1991–2020.
What's the Rainiest Month in St. Louis?
In St. Louis, May has the greatest precipitation of any month. On average, St. Louis gets 4.8 inches of precipitation in May.
May is also the month where rain is most common. 40.8% of days in May will have at least some rain or snow.
What's the Driest Month in St. Louis?
In St. Louis, February has the least precipitation of any month. On average, St. Louis gets 2.23 inches of precipitation in February.
September is the month with the lowest chance of precipitation. 24.3% of days in September will have measurable rain.
Month Precipitation % Chance
January 2.59 in 30.1
February 2.23 in 30.4
March 3.50 in 34.8
April 4.72 in 38.2
May 4.82 in 40.8
June 4.49 in 32.6
July 3.93 in 28.8
August 3.37 in 27.2
September 2.96 in 24.3
October 3.15 in 27.4
November 3.42 in 30.1
December 2.50 in 29.1
Year 41.68 in 31.2
Weather Station Details
Years Station Coordinates
1939–2024 St. Louis International Airport location
1893–1938 St. Louis location