Most Monthly Precipitation in San Juan History

This is a list of the largest monthly precipitation totals ever recorded in San Juan, Puerto Rico history from 1956–2024.

What Was the Wettest Month in San Juan History?

According to NOAA records, the most precipitation that San Juan, Puerto Rico has ever received in a single month is 18.6 inches which occurred in August 2011.

San Juan Most Rain in One Month

Rank	Precipitation	Month
1	18.6 inches	August 2011
2	17.7 inches	November 2016
3	16.8 inches	December 1981
4	16.0 inches	November 1979
5	15.8 inches	September 2017
6	15.2 inches	September 1996
7	15.1 inches	October 1970
8	15.0 inches	April 2005
9	15.0 inches	May 1965
10	14.8 inches	September 1989
11	14.5 inches	May 2013
12	14.2 inches	July 2013
13	13.6 inches	June 2011
14	13.6 inches	May 1958
15	13.5 inches	September 2022
16	12.8 inches	May 1986
17	12.5 inches	May 2010
18	12.4 inches	November 1977
19	12.2 inches	May 1987
20	12.1 inches	November 2009