Most Monthly Precipitation in Portland History

This is a list of the largest monthly precipitation totals ever recorded in Portland, Maine history from 1871–2024.

What Was the Wettest Month in Portland History?

According to NOAA records, the most precipitation that Portland, Maine has ever received in a single month is 16.9 inches which occurred in October 1996.

Portland Most Rain in One Month

Rank	Precipitation	Month
1	16.9 inches	October 1996
2	15.2 inches	August 1991
3	14.4 inches	October 2005
4	13.5 inches	November 1983
5	12.3 inches	May 2006
6	12.3 inches	January 1935
7	12.3 inches	October 1962
8	11.9 inches	January 1979
9	11.2 inches	March 2010
10	11.0 inches	March 2024
11	10.9 inches	June 1917
12	10.8 inches	July 1915
13	10.8 inches	September 2008
14	10.5 inches	June 1922
15	10.5 inches	October 1998
16	10.3 inches	November 2018
17	10.0 inches	January 1936
18	10.0 inches	March 1953
19	9.9 inches	April 1973
20	9.8 inches	November 1963