All-time weather records — Half Moon Bay, CA

Record high
102.0°F
July 28, 1982
Record low
3.0°F
February 24, 1987
Wettest day
5.50 in
December 16, 2002

Climate change signal in Half Moon Bay

16.1%

of Half Moon Bay's all-time daily heat records were set in the last decade (59 of 366 records since 2015).

8.5%

of all-time daily cold records were set in the last decade (31 of 366 records since 2015).

If records were spread evenly across the station's history, you'd expect roughly 5% per decade. Decade-by-decade, here's where each record-breaking day was set:

Decade Heat records set # Cold records set #
1930s
7
3
1940s
36
48
1950s
56
39
1960s
45
26
1970s
30
32
1980s
32
18
1990s
34
36
2000s
50
114
2010s
55
35
2020s
21
15

Records are the all-time daily extremes that are still standing — each daily record can only be held by one year. The station's earliest hot record was set in 1939, the latest in 2026. Period of observation: 1939-2026.

Records by month

Month Hottest day Coldest day Wettest day
January 75.9°F — Jan 14, 2009 27.0°F — Jan 11, 1949 5.33 in — Jan 4, 1982
February 79.0°F — Feb 27, 2026 3.0°F — Feb 24, 1987 2.92 in — Feb 3, 1998
March 86.0°F — Mar 12, 2005 28.0°F — Mar 29, 2007 3.85 in — Mar 30, 1940
April 88.0°F — Apr 6, 2016 25.0°F — Apr 9, 1982 2.36 in — Apr 4, 1941
May 96.1°F — May 16, 2008 33.1°F — May 1, 2008 1.28 in — May 27, 1990
June 90.0°F — Jun 4, 1949 36.0°F — Jun 7, 2007 1.12 in — Jun 2, 1967
July 102.0°F — Jul 28, 1982 39.9°F — Jul 8, 1982 0.60 in — Jul 8, 1974
August 93.9°F — Aug 29, 1968 41.0°F — Aug 8, 1975 0.72 in — Aug 20, 1997
September 93.9°F — Sep 11, 1983 35.1°F — Sep 30, 2007 2.56 in — Sep 19, 1959
October 93.9°F — Oct 4, 1985 33.1°F — Oct 29, 1946 4.90 in — Oct 13, 1962
November 87.1°F — Nov 1, 1966 30.0°F — Nov 9, 2020 2.83 in — Nov 18, 1982
December 79.0°F — Dec 4, 1958 18.0°F — Dec 3, 1983 5.50 in — Dec 16, 2002

Click a month to see every daily record for that month in Half Moon Bay.