Santa Rosa, CA: frost dates by year

Last spring and first fall frost at NOAA station USC00047965, 1951 to 2025, measured from daily minimum temperatures.

Elevation 166 ft, 38.456, -122.713. Download the data (JSON), NOAA daily records

Summary at 32°F

	Last spring frost	First fall frost
Median	Mar 9	Nov 24
Earliest	Jan 5 (1998)	Aug 26 (2011)
Latest	May 7 (1977)	Dec 26 (1997)
Trend	6.6 days earlier per decade	0.8 days later per decade
Years with data	65	65, 6 with no freeze

At 28°F (hard freeze) the median last spring date is Feb 2 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
2025	Feb 11	none	Jan 21	none
2024	Jan 7	Dec 10	none	none
2023	Mar 27	Nov 25	Feb 23	Nov 27
2022	Mar 12	Nov 10	Feb 25	Nov 30
2021	Jan 26	Dec 11	Jan 26	none
2020	Mar 26	Nov 9	Mar 25	none
2019	Feb 23	Nov 28	Feb 22	Nov 29
2018	Mar 5	Nov 9	Feb 24	none
2012	Apr 5	no data	Feb 27	no data
2011	Mar 1	Aug 26	Feb 26	Dec 23
2010	Mar 9	Nov 24	none	Nov 24
2009	Mar 9	Dec 4	Jan 4	Dec 8
2008	Mar 31	Dec 14	Jan 1	Dec 17
2007	Feb 23	Nov 21	Jan 23	Dec 8
2006	Mar 13	Nov 28	Feb 21	Dec 18
2005	Jan 30	Nov 27	none	Dec 6
2004	Feb 11	Nov 28	Jan 4	Nov 29
2003	Feb 10	Nov 22	Feb 9	Nov 23
2002	Mar 8	none	Jan 29	none
2001	no data	none	no data	none
2000	no data	Nov 12	no data	none
1999	Feb 11	Dec 25	none	none
1998	Jan 5	Dec 5	none	Dec 21
1997	Jan 14	Dec 26	none	none
1996	Feb 26	none	none	none
1995	Feb 15	none	none	none
1994	Feb 12	Nov 19	none	Dec 30
1993	Jan 26	Nov 24	Jan 11	Nov 25
1992	Jan 23	Dec 5	none	none
1991	Jan 30	none	Jan 1	none
1990	Feb 19	Dec 4	Feb 18	Dec 20
1989	Feb 15	Dec 10	Feb 8	Dec 27
1988	Feb 5	Dec 26	none	none
1987	Mar 22	Dec 25	Jan 16	Dec 30
1986	Feb 8	Nov 27	none	Dec 10
1985	Mar 8	Nov 12	Jan 2	Nov 12
1984	Feb 10	Dec 16	Jan 14	Dec 22
1982	Apr 7	no data	Feb 5	no data
1981	Jan 31	Dec 25	none	none
1980	Jan 30	Dec 2	Jan 30	Dec 11
1979	no data	Nov 20	no data	none
1977	May 7	Nov 19	Mar 14	Nov 19
1976	Apr 2	Nov 28	Mar 5	Nov 29
1975	Apr 17	Nov 11	Jan 30	Dec 15
1974	Mar 9	Nov 26	Jan 10	Dec 24
1973	Mar 22	Nov 4	Jan 26	none
1972	Mar 28	Nov 23	Feb 2	Dec 5
1971	Apr 21	Nov 6	Mar 2	Dec 16
1970	Apr 28	Oct 27	Jan 6	Dec 23
1969	Mar 15	Nov 17	Jan 31	Dec 1
1968	Feb 1	Nov 28	Jan 28	Dec 4
1967	Apr 28	Dec 1	Jan 17	Dec 1
1966	Mar 20	Nov 23	Mar 17	Dec 27
1965	Apr 11	no data	Jan 9	no data
1964	Apr 25	Nov 13	Mar 8	Nov 19
1963	Apr 21	Nov 22	Jan 23	Dec 11
1962	Mar 14	Nov 29	Feb 28	Dec 25
1961	Apr 19	Nov 14	Jan 22	Nov 17
1960	Apr 24	Nov 27	Jan 17	Dec 7
1959	Feb 14	Nov 5	Feb 13	Dec 6
1958	Mar 17	Nov 15	none	Nov 16
1957	Mar 23	Nov 4	Feb 6	none
1956	Mar 15	Nov 15	Feb 19	Dec 7
1955	Apr 28	Nov 15	Mar 6	Dec 29
1954	Mar 18	Nov 29	Jan 26	Nov 30
1953	Apr 13	Dec 14	Mar 3	Dec 31
1952	Mar 22	Nov 3	Mar 13	Nov 24
1951	Mar 17	Nov 23	Mar 10	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.