Frost history / Half Moon Bay, CA
Half Moon Bay, CA: frost dates by year
Last spring and first fall frost at NOAA station USC00043714, 1951 to 2025, measured from daily minimum temperatures.
Elevation 27 ft, 37.472, -122.443. Download the data (JSON), NOAA daily records
Summary at 32°F
| Last spring frost | First fall frost | |
|---|---|---|
| Median | Feb 10 | Dec 10 |
| Earliest | Jan 1 (1952) | Nov 9 (2020) |
| Latest | Apr 30 (2008) | Dec 30 (1959) |
| Trend | 7.1 days later per decade | little change (less than half a day per decade) |
| Years with data | 67, 30 with no freeze | 69, 40 with no freeze |
At 28°F (hard freeze) the median last spring date is Jan 28 and the median first fall date is Dec 14.
The trend is a straight-line fit through the years with a freeze. A positive spring trend means the last frost now comes later. Short or patchy records give noisy trends.
Chart
Last spring frost (32°F)
First fall frost (32°F)
Dots are single years. The gray line is the median, the green line the fitted trend.
Year by year
| Year | Last spring 32°F | First fall 32°F | Last spring 28°F | First fall 28°F |
|---|---|---|---|---|
| 2025 | Feb 10 | none | none | none |
| 2024 | none | none | none | none |
| 2023 | Mar 27 | none | none | none |
| 2022 | Mar 12 | Nov 30 | none | none |
| 2021 | Jan 21 | Dec 11 | none | none |
| 2020 | Feb 5 | Nov 9 | none | none |
| 2019 | Feb 23 | Dec 27 | none | none |
| 2018 | Feb 28 | Nov 10 | Feb 24 | none |
| 2017 | Mar 2 | Dec 22 | none | none |
| 2016 | none | Dec 17 | none | none |
| 2015 | none | Dec 27 | none | none |
| 2014 | none | none | none | none |
| 2013 | Feb 27 | Dec 4 | none | Dec 4 |
| 2012 | Mar 8 | Dec 19 | Jan 17 | none |
| 2011 | Feb 27 | Dec 18 | none | none |
| 2010 | none | Nov 24 | none | none |
| 2009 | Apr 4 | Dec 6 | Jan 4 | Dec 8 |
| 2008 | Apr 30 | Dec 20 | none | none |
| 2007 | Apr 16 | Nov 23 | Mar 29 | none |
| 2006 | Mar 13 | Dec 18 | none | Dec 28 |
| 2005 | none | Nov 27 | none | none |
| 2004 | Feb 17 | Nov 30 | none | none |
| 2000 | Jan 1 | none | none | none |
| 1999 | none | none | none | none |
| 1998 | none | Dec 21 | none | Dec 22 |
| 1997 | none | none | none | none |
| 1996 | none | none | none | none |
| 1995 | none | none | none | none |
| 1994 | no data | Dec 25 | no data | none |
| 1993 | none | no data | none | no data |
| 1992 | none | none | none | none |
| 1991 | Mar 16 | none | none | none |
| 1990 | Feb 14 | Dec 20 | none | Dec 20 |
| 1989 | Feb 7 | none | Feb 5 | none |
| 1987 | no data | none | no data | none |
| 1986 | none | none | none | none |
| 1985 | none | no data | none | no data |
| 1984 | Jan 13 | none | none | none |
| 1983 | Jan 20 | none | Jan 20 | none |
| 1982 | none | none | none | none |
| 1981 | none | none | none | none |
| 1980 | Jan 29 | none | none | none |
| 1979 | Feb 3 | none | none | none |
| 1978 | none | Dec 8 | none | none |
| 1977 | none | none | none | none |
| 1976 | Apr 1 | none | none | none |
| 1975 | Jan 30 | none | none | none |
| 1974 | none | none | none | none |
| 1973 | no data | none | no data | none |
| 1972 | Mar 26 | Dec 8 | none | Dec 9 |
| 1971 | none | none | none | none |
| 1970 | none | none | none | none |
| 1969 | Jan 31 | none | none | none |
| 1968 | none | Dec 20 | none | none |
| 1967 | none | none | none | none |
| 1966 | Mar 3 | none | none | none |
| 1965 | Jan 1 | none | none | none |
| 1964 | none | none | none | none |
| 1963 | Jan 13 | none | none | none |
| 1962 | Jan 23 | none | none | none |
| 1961 | none | none | none | none |
| 1960 | Jan 1 | none | none | none |
| 1959 | none | Dec 30 | none | none |
| 1958 | none | Nov 17 | none | none |
| 1957 | Jan 3 | none | none | none |
| 1956 | none | Nov 22 | none | none |
| 1955 | Jan 8 | Nov 20 | none | none |
| 1954 | none | none | none | none |
| 1953 | no data | none | no data | none |
| 1952 | Jan 1 | none | none | none |
| 1951 | Jan 31 | Dec 10 | none | none |
"none" means the station recorded no freeze at that threshold in that half of the year. "no data" means more than 10% of the season's daily readings were missing. Years with no usable data are left out. See the methodology for the rules, and the ZIP lookup for 1991 to 2020 frost probabilities.