Frost history / Ft Ross, CA
Ft Ross, CA: frost dates by year
Last spring and first fall frost at NOAA station USC00043191, 1951 to 2022, measured from daily minimum temperatures.
Elevation 112 ft, 38.515, -123.245. Download the data (JSON), NOAA daily records
Summary at 32°F
| Last spring frost | First fall frost | |
|---|---|---|
| Median | Mar 3 | Dec 7 |
| Earliest | Jan 1 (1960) | Aug 1 (2020) |
| Latest | May 19 (1990) | Dec 31 (1975) |
| Trend | 6.6 days later per decade | 7.2 days earlier per decade |
| Years with data | 43, 13 with no freeze | 41, 22 with no freeze |
At 28°F (hard freeze) the median last spring date is Apr 4 and the median first fall date is Dec 8.
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 |
|---|---|---|---|---|
| 2022 | Feb 23 | none | none | none |
| 2021 | Mar 23 | Dec 28 | none | none |
| 2020 | no data | Aug 1 | no data | Oct 6 |
| 1997 | Jan 14 | no data | none | no data |
| 1996 | none | no data | none | no data |
| 1994 | Apr 26 | no data | Apr 26 | no data |
| 1993 | Feb 15 | no data | none | no data |
| 1992 | Apr 23 | Dec 18 | Apr 4 | none |
| 1990 | May 19 | Dec 3 | May 19 | Dec 20 |
| 1988 | no data | Dec 25 | no data | none |
| 1986 | May 7 | Dec 1 | none | none |
| 1985 | May 12 | Nov 9 | none | Nov 12 |
| 1984 | none | Dec 19 | none | none |
| 1983 | none | none | none | none |
| 1982 | May 2 | none | Apr 27 | none |
| 1981 | none | none | none | none |
| 1980 | Jan 29 | Aug 14 | none | none |
| 1979 | Feb 2 | none | none | none |
| 1978 | none | no data | none | no data |
| 1977 | Mar 30 | none | Mar 30 | none |
| 1976 | Mar 3 | none | Jan 3 | none |
| 1975 | Jan 31 | Dec 31 | none | none |
| 1974 | Mar 5 | Dec 26 | none | none |
| 1973 | no data | none | no data | none |
| 1972 | Mar 26 | Dec 5 | none | Dec 8 |
| 1971 | Feb 26 | Dec 7 | none | none |
| 1970 | Apr 25 | none | none | none |
| 1969 | Jan 29 | none | none | none |
| 1968 | none | Dec 20 | none | Dec 26 |
| 1967 | none | Dec 13 | none | none |
| 1966 | Mar 3 | none | none | none |
| 1965 | none | none | none | none |
| 1964 | none | none | none | none |
| 1963 | Jan 12 | none | none | none |
| 1962 | Feb 27 | none | Feb 27 | none |
| 1961 | none | none | none | none |
| 1960 | Jan 1 | none | none | none |
| 1959 | Jan 3 | none | none | none |
| 1958 | none | Nov 16 | none | none |
| 1957 | Feb 3 | none | none | none |
| 1956 | Mar 6 | Dec 7 | none | none |
| 1955 | none | none | none | none |
| 1954 | Jan 25 | Dec 26 | none | none |
| 1953 | Apr 8 | none | none | none |
| 1952 | none | none | none | none |
| 1951 | Mar 17 | Dec 7 | 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.