Frost history / Palo Alto, CA
Palo Alto, CA: frost dates by year
Last spring and first fall frost at NOAA station USC00046646, 1954 to 2017, measured from daily minimum temperatures.
Elevation 25 ft, 37.444, -122.140. Download the data (JSON), NOAA daily records
Summary at 32°F
| Last spring frost | First fall frost | |
|---|---|---|
| Median | Feb 7 | Dec 1 |
| Earliest | Jan 1 (2016) | Nov 11 (1992) |
| Latest | Apr 25 (1964) | Dec 29 (1955) |
| Trend | 3.3 days earlier per decade | 1.2 days later per decade |
| Years with data | 46, 5 with no freeze | 47, 5 with no freeze |
At 28°F (hard freeze) the median last spring date is Jan 14 and the median first fall date is Dec 12.
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 |
|---|---|---|---|---|
| 2017 | Feb 12 | no data | none | no data |
| 2016 | Jan 1 | no data | none | no data |
| 2014 | no data | Dec 27 | no data | none |
| 2012 | Apr 5 | Dec 13 | Mar 4 | Dec 13 |
| 2011 | no data | Dec 5 | no data | Dec 23 |
| 2007 | Jan 25 | no data | Jan 16 | no data |
| 2006 | Feb 22 | Nov 30 | none | Dec 19 |
| 2005 | Jan 14 | Dec 6 | none | none |
| 2004 | no data | Nov 29 | no data | Dec 4 |
| 1998 | none | no data | none | no data |
| 1997 | Jan 15 | Dec 23 | Jan 14 | none |
| 1996 | Feb 27 | none | none | none |
| 1995 | none | none | none | none |
| 1994 | Mar 24 | Nov 19 | Feb 14 | none |
| 1993 | Feb 1 | no data | Jan 6 | no data |
| 1992 | Jan 24 | Nov 11 | none | Dec 26 |
| 1991 | Jan 31 | Dec 5 | Jan 3 | none |
| 1990 | no data | Dec 2 | no data | Dec 21 |
| 1989 | Feb 14 | Nov 28 | Feb 7 | none |
| 1988 | Feb 6 | Dec 26 | none | Dec 29 |
| 1987 | no data | Dec 25 | no data | none |
| 1986 | none | none | none | none |
| 1985 | no data | Nov 13 | no data | Dec 12 |
| 1984 | Jan 18 | Dec 17 | none | none |
| 1983 | Jan 21 | Dec 5 | Jan 14 | none |
| 1982 | Feb 7 | Nov 14 | Jan 24 | Dec 11 |
| 1981 | none | none | none | none |
| 1980 | Mar 26 | Nov 15 | none | Dec 11 |
| 1979 | Feb 5 | Nov 20 | Feb 4 | none |
| 1978 | none | Nov 12 | none | Dec 8 |
| 1977 | Mar 31 | no data | none | no data |
| 1976 | Mar 6 | Nov 28 | Jan 3 | Dec 27 |
| 1975 | Apr 18 | Nov 19 | Jan 30 | Dec 15 |
| 1974 | Feb 7 | Dec 24 | Jan 2 | Dec 24 |
| 1973 | Jan 27 | none | Jan 7 | none |
| 1972 | Feb 1 | Dec 1 | none | Dec 5 |
| 1971 | Mar 6 | Dec 16 | none | none |
| 1970 | Jan 29 | Dec 25 | Jan 6 | none |
| 1969 | Feb 3 | Nov 30 | none | none |
| 1968 | Jan 12 | Dec 3 | Jan 6 | Dec 21 |
| 1966 | no data | Nov 24 | no data | Dec 27 |
| 1965 | Feb 12 | Dec 15 | Jan 1 | Dec 16 |
| 1964 | Apr 25 | Nov 14 | none | Nov 18 |
| 1963 | Mar 18 | Dec 10 | Jan 22 | Dec 12 |
| 1962 | Mar 13 | Nov 29 | Feb 27 | Dec 25 |
| 1961 | Jan 21 | Nov 16 | Jan 20 | Nov 17 |
| 1960 | Feb 24 | Dec 8 | Jan 5 | Dec 8 |
| 1959 | Feb 13 | Dec 6 | none | none |
| 1958 | Jan 22 | Nov 17 | none | Nov 17 |
| 1957 | Feb 5 | Dec 1 | Jan 31 | none |
| 1956 | Mar 7 | Nov 20 | none | Dec 9 |
| 1955 | Mar 5 | Dec 29 | Jan 8 | none |
| 1954 | Mar 14 | Nov 30 | none | Nov 30 |
"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.