Frost history / Clearlake 4 Se, CA
Clearlake 4 Se, CA: frost dates by year
Last spring and first fall frost at NOAA station USC00041806, 1955 to 2025, measured from daily minimum temperatures.
Elevation 1,349 ft, 38.924, -122.567. Download the data (JSON), NOAA daily records
Summary at 32°F
| Last spring frost | First fall frost | |
|---|---|---|
| Median | Apr 25 | Oct 27 |
| Earliest | Mar 14 (1990) | Sep 19 (1965) |
| Latest | May 18 (1974) | Nov 25 (2025) |
| Trend | 6.7 days earlier per decade | 5.6 days later per decade |
| Years with data | 29 | 30 |
At 28°F (hard freeze) the median last spring date is Apr 1 and the median first fall date is Nov 10.
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 | Mar 19 | Nov 25 | Feb 13 | none |
| 2006 | no data | Oct 27 | no data | Nov 10 |
| 1992 | no data | Nov 9 | no data | Nov 10 |
| 1991 | no data | Nov 1 | no data | Nov 16 |
| 1990 | Mar 14 | Nov 9 | Mar 14 | Nov 10 |
| 1989 | Mar 26 | Oct 30 | Mar 4 | Nov 27 |
| 1984 | Apr 27 | no data | Feb 26 | no data |
| 1983 | May 10 | Nov 8 | Feb 5 | Dec 21 |
| 1982 | Apr 16 | Oct 27 | Apr 9 | Nov 11 |
| 1981 | Apr 15 | Oct 15 | Mar 6 | Nov 29 |
| 1980 | Apr 12 | Oct 17 | Apr 7 | Nov 12 |
| 1979 | Apr 19 | Oct 21 | Feb 15 | Nov 14 |
| 1978 | Apr 22 | Nov 1 | Jan 27 | Nov 14 |
| 1977 | May 7 | Nov 4 | Mar 31 | Nov 9 |
| 1976 | Apr 13 | Oct 19 | Apr 11 | Nov 28 |
| 1975 | Apr 29 | Oct 24 | Apr 17 | Nov 9 |
| 1974 | May 18 | Nov 2 | May 18 | Nov 19 |
| 1973 | Mar 29 | Oct 29 | Mar 22 | Nov 4 |
| 1972 | Apr 30 | Oct 28 | Mar 30 | Nov 6 |
| 1971 | Apr 21 | Oct 1 | Apr 1 | Oct 17 |
| 1970 | May 12 | Oct 26 | Apr 29 | Oct 27 |
| 1969 | Apr 16 | Oct 5 | Mar 19 | Nov 17 |
| 1968 | May 14 | no data | May 6 | no data |
| 1967 | May 13 | Oct 16 | Apr 28 | Nov 25 |
| 1966 | May 5 | Oct 14 | Apr 29 | Oct 15 |
| 1965 | May 7 | Sep 19 | Apr 7 | Nov 22 |
| 1964 | May 15 | Oct 16 | May 4 | Nov 14 |
| 1963 | no data | Oct 27 | no data | Oct 31 |
| 1962 | Apr 30 | no data | Mar 18 | no data |
| 1961 | Apr 25 | Oct 22 | Mar 7 | Oct 22 |
| 1959 | no data | Nov 6 | no data | Nov 9 |
| 1957 | Apr 15 | no data | Apr 9 | no data |
| 1956 | Apr 13 | Oct 15 | Apr 6 | Oct 24 |
| 1955 | Apr 29 | Oct 7 | Apr 27 | Oct 31 |
"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.