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Half Moon Bay September Monthly Average Temperatures

A time series of monthly average September temperatures in Half Moon Bay, California from 1939–2021.
Hottest September in Half Moon Bay History
The hottest September in Half Moon Bay, California history occurred in 2014, when the average temperature of 63.3 °F was 4.3 °F higher than normal.
Coldest September in Half Moon Bay History
The coldest September in Half Moon Bay, California history occurred in 1955, when the average temperature of 55.0 °F was 3.9 °F below normal.
Half Moon Bay Average September Temperature by Year
Year Temperature (°F) to Normal (°F)
2021 58.5 -0.5
2020 60.9 1.9
2019 61.1 2.1
2018 57.3 -1.7
2017 62.9 3.9
2016 58.4 -0.6
2015 60.0 1.1
2014 63.3 4.3
2013 60.3 1.4
2012 56.1 -2.8
2011 58.2 -0.7
2010 58.0 -0.9
2009 58.8 -0.1
2008 57.2 -1.8
2007 58.6 -0.4
2006 56.3 -2.6
2005 57.4 -1.5
2004 57.6 -1.4
2001 58.0 -1.0
2000 60.7 1.8
1998 59.1 0.1
1997 63.1 4.1
1996 57.3 -1.6
1995 59.5 0.6
1992 58.7 -0.3
1991 58.0 -1.0
1990 60.0 1.1
1989 59.0 0.0
1988 57.1 -1.9
1987 59.0 0.0
1986 59.0 0.0
1985 59.5 0.5
1984 61.2 2.2
1982 59.4 0.4
1981 58.5 -0.4
1980 58.5 -0.5
1979 61.7 2.8
1978 60.0 1.0
1976 60.2 1.3
1975 57.0 -2.0
1974 59.5 0.5
1973 59.2 0.2
1972 60.4 1.4
1971 59.0 0.0
1970 58.4 -0.5
1969 57.5 -1.5
1968 59.3 0.4
1967 61.7 2.8
1966 59.9 1.0
1965 58.7 -0.2
1964 58.6 -0.4
1962 57.4 -1.6
1961 60.4 1.5
1960 57.8 -1.1
1959 60.0 1.1
1958 62.1 3.2
1957 60.7 1.8
1956 59.5 0.5
1955 55.0 -3.9
1954 57.9 -1.1
1953 61.4 2.4
1952 60.8 1.8
1951 59.4 0.4
1950 58.3 -0.6
1948 56.7 -2.3
1947 59.3 0.3
1946 58.7 -0.3
1945 58.1 -0.9
1944 56.2 -2.8
1943 60.2 1.3
1942 58.5 -0.5
1941 59.6 0.6
1940 62.1 3.1
1939 61.9 3.0