Most Monthly Precipitation in St. Catharines History

This is a list of the largest monthly precipitation totals ever recorded in St. Catharines, Ontario history from 1882–2024.

What Was the Wettest Month in St. Catharines History?

According to NOAA records, the most precipitation that St. Catharines, Ontario has ever received in a single month is 23.9 cm which occurred in September 1977.

Month to date though April 26, 2024: 8.9 cm

St. Catharines Most Rain in One Month

Rank	Precipitation	Month
1	23.9 cm	September 1977
2	23.7 cm	September 1945
3	22.6 cm	June 2000
4	18.3 cm	January 2009
5	18.1 cm	September 2012
6	17.3 cm	August 1954
7	17.0 cm	May 1883
8	17.0 cm	May 2003
9	17.0 cm	November 1985
10	16.6 cm	October 1954
11	16.6 cm	July 1992
12	16.5 cm	August 1955
13	16.0 cm	June 1928
14	15.9 cm	August 1903
15	15.6 cm	August 1915
16	15.5 cm	November 2003
17	15.3 cm	May 2004
18	15.2 cm	August 1977
19	15.0 cm	June 1922
20	15.0 cm	September 1924