Half Moon Bay September Precipitation Totals

A time series of total precipitation in the month of September in Half Moon Bay, California from 1939–2023.

Rainiest September in Half Moon Bay History

The rainiest September in Half Moon Bay, California history happened in 1959, with 3.66 inches of total precipitation.

Driest September in Half Moon Bay History

There have been 15 times where no rain was recorded in Half Moon Bay, California for the entire month of September. The most recent time this happened was 2016.

Half Moon Bay Average September Precipitation by Year

Read important notes
Click column headers to sort

Year	Precipitation (inches)
2023	0.24
2022	0.45
2021	0.18
2020	0.04
2019	0.32
2018	0.03
2017	0.24
2016	0.00
2015	0.11
2014	0.52
2013	0.85
2012	0.04
2011	0.03
2010	0.30
2009	0.53
2008	0.07
2007	0.27
2006	0.07
2005	0.15
2004	0.29
2002	0.17
2001	0.26
2000	0.41
1999	0.21
1998	0.25
1997	0.08
1996	0.20
1995	0.15
1994	0.09
1992	0.12
1991	0.25
1990	0.33
1989	0.46
1988	0.02
1987	0.00
1986	2.22
1985	0.40
1984	0.18
1983	0.80
1982	1.73
1981	0.37
1980	0.18
1979	0.00
1978	0.00
1977	1.59
1976	0.59
1975	0.02
1974	0.00
1973	0.62
1972	0.98
1971	0.40
1970	0.00
1969	0.21
1968	0.00
1967	0.00
1966	0.25
1965	0.00
1964	0.00
1963	0.09
1962	0.51
1961	0.57
1960	0.00
1959	3.66
1958	0.18
1957	1.08
1956	0.45
1955	0.28
1954	0.08
1953	0.12
1952	0.15
1951	0.28
1950	0.08
1948	0.04
1947	0.00
1946	0.08
1945	0.04
1944	0.00
1943	0.00
1942	0.16
1941	0.00
1940	0.37
1939	0.48

Notes

Its possible for precipitation totals to include both rain and melted snowfall
Months with more than 10% missing data are excluded