Most Monthly Precipitation in Guam History

This is a list of the largest monthly precipitation totals ever recorded in Guam history from 1945–2024.
What Was the Wettest Month in Guam History?
According to NOAA records, the most precipitation that Guam has ever received in a single month is 38.5 inches which occurred in August 1997.
Month to date though March 26, 2024: 1.4 inches
Guam Most Rain in One Month
Rank Precipitation Month
1 38.5 inches August 1997
2 38.0 inches June 2004
3 37.6 inches August 1992
4 37.3 inches August 2004
5 34.7 inches May 1976
6 32.2 inches September 2013
7 31.2 inches May 2023
8 29.8 inches July 2002
9 29.4 inches July 2014
10 26.7 inches October 2021
11 26.5 inches October 1953
12 26.4 inches August 2012
13 26.1 inches August 2009
14 25.7 inches December 2002
15 25.3 inches October 1979
16 24.8 inches August 2001
17 24.4 inches August 1986
18 24.3 inches September 1982
19 24.3 inches August 1981
20 23.9 inches September 1980