Most Monthly Precipitation in Boulder History

This is a list of the largest monthly precipitation totals ever recorded in Boulder, Colorado history from 1893–2024.

What Was the Wettest Month in Boulder History?

According to NOAA records, the most precipitation that Boulder, Colorado has ever received in a single month is 18.2 inches which occurred in September 2013.

Month to date though April 25, 2024: 1.6 inches

Boulder Most Rain in One Month

Rank	Precipitation	Month
1	18.2 inches	September 2013
2	9.6 inches	May 1995
3	9.3 inches	May 1957
4	9.2 inches	April 1900
5	8.7 inches	May 1969
6	8.0 inches	May 1978
7	7.8 inches	May 2015
8	7.6 inches	April 1999
9	7.5 inches	August 1951
10	7.5 inches	July 1919
11	7.4 inches	June 1949
12	7.0 inches	May 1935
13	6.9 inches	April 1942
14	6.9 inches	April 1957
15	6.8 inches	April 1944
16	6.7 inches	April 1905
17	6.3 inches	May 2017
18	6.2 inches	May 1917
19	6.0 inches	October 1942
20	6.0 inches	June 1987