Frost history / San Francisco Intl Ap, CA
San Francisco Intl Ap, CA: frost dates by year
Last spring and first fall frost at NOAA station USW00023234, 1951 to 2024, measured from daily minimum temperatures.
Elevation 8 ft, 37.620, -122.365. Download the data (JSON), NOAA daily records
Summary at 32°F
| Last spring frost | First fall frost | |
|---|---|---|
| Median | Jan 14 | Dec 17 |
| Earliest | Jan 1 (1965) | Nov 24 (1952) |
| Latest | Mar 3 (1966) | Dec 28 (1966) |
| Trend | 1.1 days earlier per decade | 3.5 days later per decade |
| Years with data | 74, 51 with no freeze | 74, 61 with no freeze |
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 |
|---|---|---|---|---|
| 2024 | none | none | none | none |
| 2023 | none | none | none | none |
| 2022 | none | none | none | none |
| 2021 | none | none | none | none |
| 2020 | none | none | none | none |
| 2019 | none | none | none | none |
| 2018 | none | none | none | none |
| 2017 | none | none | none | none |
| 2016 | none | none | none | none |
| 2015 | none | none | none | none |
| 2014 | none | none | none | none |
| 2013 | none | none | none | none |
| 2012 | none | none | none | none |
| 2011 | none | none | none | none |
| 2010 | none | none | none | none |
| 2009 | none | none | none | none |
| 2008 | none | none | none | none |
| 2007 | Jan 14 | none | none | none |
| 2006 | none | none | none | none |
| 2005 | none | none | none | none |
| 2004 | none | none | none | none |
| 2003 | none | none | none | none |
| 2002 | none | none | none | none |
| 2001 | none | none | none | none |
| 2000 | none | none | none | none |
| 1999 | none | none | none | none |
| 1998 | none | Dec 21 | none | none |
| 1997 | none | none | none | none |
| 1996 | none | none | none | none |
| 1995 | none | none | none | none |
| 1994 | none | none | none | none |
| 1993 | none | none | none | none |
| 1992 | none | none | none | none |
| 1991 | none | none | none | none |
| 1990 | none | Dec 21 | none | Dec 21 |
| 1989 | Feb 7 | none | none | none |
| 1988 | none | none | none | none |
| 1987 | none | none | none | none |
| 1986 | none | none | none | none |
| 1985 | none | none | none | none |
| 1984 | none | none | none | none |
| 1983 | none | none | none | none |
| 1982 | none | none | none | none |
| 1981 | none | none | none | none |
| 1980 | Jan 30 | none | none | none |
| 1979 | Feb 3 | none | none | none |
| 1978 | none | Dec 8 | none | none |
| 1977 | none | none | none | none |
| 1976 | Jan 2 | none | none | none |
| 1975 | Jan 30 | none | none | none |
| 1974 | Jan 8 | Dec 25 | none | none |
| 1973 | Jan 7 | none | none | none |
| 1972 | Jan 5 | Dec 5 | none | Dec 9 |
| 1971 | Jan 5 | none | none | none |
| 1970 | none | none | none | none |
| 1969 | none | none | none | none |
| 1968 | Jan 6 | Dec 21 | none | none |
| 1967 | none | Dec 15 | none | none |
| 1966 | Mar 3 | Dec 28 | none | none |
| 1965 | Jan 1 | Dec 17 | none | none |
| 1964 | none | none | none | none |
| 1963 | Jan 20 | none | none | none |
| 1962 | Jan 24 | Dec 25 | none | none |
| 1961 | Jan 4 | none | none | none |
| 1960 | Jan 2 | none | none | none |
| 1959 | none | none | none | none |
| 1958 | none | none | none | none |
| 1957 | Jan 10 | none | none | none |
| 1956 | Feb 1 | none | none | none |
| 1955 | Feb 4 | none | none | none |
| 1954 | Jan 25 | Nov 30 | none | none |
| 1953 | none | none | none | none |
| 1952 | Jan 3 | Nov 24 | none | none |
| 1951 | Mar 3 | 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.