Frost history / Porterville, CA
Porterville, CA: frost dates by year
Last spring and first fall frost at NOAA station USC00047077, 1951 to 2003, measured from daily minimum temperatures.
Elevation 393 ft, 36.068, -119.020. Download the data (JSON), NOAA daily records
Summary at 32°F
| Last spring frost | First fall frost | |
|---|---|---|
| Median | Feb 13 | Nov 28 |
| Earliest | Jan 6 (1998) | Nov 1 (1956) |
| Latest | Jun 1 (1971) | Dec 27 (1966) |
| Trend | 4.5 days earlier per decade | 2.1 days later per decade |
| Years with data | 53, 2 with no freeze | 52 |
At 28°F (hard freeze) the median last spring date is Jan 27 and the median first fall date is Dec 13.
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 |
|---|---|---|---|---|
| 2003 | Feb 7 | no data | none | no data |
| 2002 | Mar 19 | Dec 11 | none | Dec 11 |
| 2001 | Feb 8 | Dec 16 | none | none |
| 2000 | Jan 9 | Nov 13 | none | none |
| 1999 | Apr 1 | Dec 8 | Jan 10 | none |
| 1998 | Jan 6 | Dec 7 | none | Dec 21 |
| 1997 | Jan 8 | Dec 10 | none | Dec 25 |
| 1996 | Feb 23 | Dec 19 | none | none |
| 1995 | none | Dec 17 | none | none |
| 1994 | Feb 22 | Nov 19 | Jan 31 | Nov 20 |
| 1993 | Apr 6 | Nov 24 | Apr 6 | Nov 25 |
| 1992 | Feb 3 | Nov 30 | Jan 25 | Dec 19 |
| 1991 | Feb 1 | Nov 28 | Jan 2 | Nov 30 |
| 1990 | Feb 20 | Nov 27 | Feb 15 | Dec 20 |
| 1989 | Feb 15 | Nov 27 | Feb 8 | Dec 12 |
| 1988 | Feb 6 | Dec 7 | none | Dec 27 |
| 1987 | Feb 26 | Nov 27 | Jan 21 | Dec 24 |
| 1986 | Feb 9 | Dec 2 | none | none |
| 1985 | Feb 6 | Nov 13 | none | Dec 13 |
| 1984 | Jan 20 | Dec 15 | none | none |
| 1983 | Jan 20 | Nov 27 | none | none |
| 1982 | Feb 6 | Dec 16 | Jan 8 | Dec 25 |
| 1981 | Feb 1 | Dec 24 | none | none |
| 1980 | none | Nov 20 | none | Dec 12 |
| 1979 | Mar 2 | Nov 20 | Jan 27 | none |
| 1978 | Jan 27 | Nov 16 | none | Dec 6 |
| 1977 | Mar 14 | Nov 20 | Jan 15 | Nov 20 |
| 1976 | Jan 22 | Nov 28 | Jan 4 | Nov 29 |
| 1975 | Feb 22 | Nov 18 | Jan 30 | Dec 15 |
| 1974 | Feb 15 | Nov 30 | Jan 3 | Dec 23 |
| 1973 | Jan 27 | Nov 4 | Jan 7 | none |
| 1972 | Feb 4 | Dec 5 | Feb 4 | Dec 6 |
| 1971 | Jun 1 | Nov 16 | Mar 2 | Dec 5 |
| 1970 | Jan 29 | Dec 13 | Jan 7 | none |
| 1969 | Feb 13 | Nov 28 | Jan 29 | Dec 29 |
| 1968 | Jan 30 | Nov 28 | Jan 6 | Dec 5 |
| 1967 | Mar 30 | Dec 1 | Jan 9 | Dec 13 |
| 1966 | Mar 4 | Dec 27 | Mar 4 | Dec 28 |
| 1965 | Feb 13 | Dec 16 | none | Dec 18 |
| 1964 | Mar 9 | Nov 14 | Jan 14 | Nov 15 |
| 1963 | Jan 28 | Dec 11 | Jan 27 | Dec 13 |
| 1962 | Mar 1 | Nov 29 | Feb 28 | Dec 25 |
| 1961 | Jan 22 | Nov 17 | Jan 21 | none |
| 1960 | Jan 18 | Nov 28 | Jan 6 | Dec 8 |
| 1959 | Feb 13 | Dec 7 | Feb 9 | Dec 14 |
| 1958 | Mar 9 | Nov 16 | none | Nov 18 |
| 1957 | Feb 5 | Dec 1 | Feb 5 | none |
| 1956 | Mar 8 | Nov 1 | Feb 17 | Dec 8 |
| 1955 | Apr 3 | Nov 12 | Feb 6 | none |
| 1954 | Mar 15 | Nov 30 | Jan 14 | Dec 27 |
| 1953 | Apr 9 | Nov 19 | Feb 22 | Dec 23 |
| 1952 | Mar 8 | Nov 25 | Feb 18 | Nov 26 |
| 1951 | Mar 3 | Dec 6 | Jan 31 | Dec 9 |
"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.