Fenn Rs, ID: frost dates by year

Last spring and first fall frost at NOAA station USC00103143, 1951 to 2025, measured from daily minimum temperatures.

Elevation 1,560 ft, 46.093, -115.536. Download the data (JSON), NOAA daily records

Summary at 32°F

	Last spring frost	First fall frost
Median	Apr 30	Oct 12
Earliest	Mar 30 (1969)	Sep 4 (1969)
Latest	Jun 9 (1984)	Nov 19 (2010)
Trend	0.6 days earlier per decade	3.2 days later per decade
Years with data	58	61

At 28°F (hard freeze) the median last spring date is Apr 4 and the median first fall date is Oct 31.

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	Apr 24	Nov 11	Mar 9	Dec 29
2023	Apr 16	no data	Apr 7	no data
2021	no data	Oct 13	no data	Nov 22
2018	Apr 19	Oct 12	Mar 25	Oct 14
2017	May 17	Oct 30	Apr 17	Oct 31
2016	Mar 31	Oct 12	Mar 19	Dec 5
2015	no data	Nov 7	no data	Nov 21
2014	Apr 21	Nov 11	Apr 14	Nov 11
2013	May 3	Oct 29	Apr 19	Oct 29
2012	May 13	Oct 4	Mar 8	Oct 5
2011	Apr 25	Oct 28	Mar 13	Nov 2
2010	May 10	Nov 19	May 4	Nov 21
2009	May 2	Oct 6	Mar 27	Oct 10
2008	May 3	Oct 11	Apr 21	Oct 11
2007	Apr 22	Oct 27	Apr 4	Nov 2
2006	May 11	Oct 10	Mar 20	Oct 31
2005	Apr 30	Nov 8	Mar 26	Nov 15
2004	no data	Oct 25	no data	Nov 29
2003	May 18	Oct 25	Feb 28	Oct 25
1999	May 12	Oct 2	Apr 16	Oct 17
1998	Apr 14	Oct 31	Mar 31	Dec 18
1997	no data	Oct 26	no data	Nov 11
1996	May 5	Oct 17	Mar 29	Oct 21
1995	May 14	no data	Mar 31	no data
1994	no data	Oct 8	no data	Nov 8
1993	Apr 20	no data	Mar 15	no data
1992	May 12	Nov 11	Apr 8	Nov 24
1991	Apr 14	Oct 4	Mar 25	Oct 30
1989	Apr 13	Oct 16	Mar 5	Nov 1
1988	Apr 11	Oct 27	Apr 10	Dec 2
1987	Apr 21	Oct 10	Apr 2	Oct 14
1986	May 23	Oct 11	Feb 21	Oct 12
1985	no data	Sep 28	no data	Sep 29
1984	Jun 9	Sep 25	Jun 9	Oct 17
1983	May 14	Sep 20	Apr 16	Nov 22
1982	May 5	Oct 18	Apr 21	Nov 8
1981	Apr 15	Oct 5	Mar 13	Oct 21
1980	Apr 12	Oct 10	Apr 3	Oct 23
1979	Apr 21	Nov 2	Mar 24	Nov 2
1978	Apr 18	Oct 13	Apr 13	Oct 25
1977	Apr 21	Oct 11	Apr 19	Nov 9
1976	Apr 30	Oct 18	Mar 15	Oct 18
1975	May 2	Oct 23	Apr 11	Nov 10
1974	Apr 17	Oct 6	Mar 24	Oct 6
1973	May 21	Oct 3	May 1	Oct 3
1972	no data	Sep 26	no data	Oct 31
1971	Apr 27	Sep 16	Apr 5	Oct 28
1970	May 2	Sep 13	Apr 19	Oct 15
1969	Mar 30	Sep 4	Mar 30	Oct 12
1968	May 6	Oct 3	Apr 23	Oct 9
1967	May 27	Nov 3	Apr 16	Nov 3
1966	no data	Oct 10	no data	Oct 19
1965	May 19	Sep 16	Mar 26	Sep 19
1964	no data	Oct 9	no data	Nov 16
1963	Apr 20	no data	Apr 3	no data
1962	Apr 30	no data	Mar 17	no data
1961	Apr 21	Sep 29	Apr 7	Nov 2
1960	Apr 18	Oct 29	Mar 18	Oct 29
1959	May 6	no data	Apr 7	no data
1958	Apr 29	Oct 22	Mar 17	Nov 16
1957	Apr 16	Oct 20	Mar 27	Nov 3
1956	May 1	Oct 20	Apr 6	Nov 1
1955	May 9	Oct 24	May 9	Nov 2
1954	May 2	Oct 14	May 2	Oct 14
1953	May 5	Oct 4	Apr 11	Oct 23
1952	Apr 22	Oct 5	Apr 11	Oct 14
1951	Jun 2	Sep 21	May 29	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.