Alma Dam 4, WI: frost dates by year

Last spring and first fall frost at NOAA station USC00470124, 1952 to 2025, measured from daily minimum temperatures.

Elevation 670 ft, 44.327, -91.919. Download the data (JSON), NOAA daily records

Summary at 32°F

	Last spring frost	First fall frost
Median	Apr 24	Oct 13
Earliest	Apr 5 (1984)	Sep 20 (1973)
Latest	May 17 (1973)	Nov 19 (2016)
Trend	little change (less than half a day per decade)	1.5 days later per decade
Years with data	73	71

At 28°F (hard freeze) the median last spring date is Apr 12 and the median first fall date is Oct 28.

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 9	Oct 25	Apr 9	Nov 9
2024	Apr 25	Oct 16	Mar 30	Nov 21
2023	Apr 18	Oct 29	Apr 7	Oct 30
2022	Apr 28	Oct 18	Apr 20	Oct 18
2021	Apr 26	Oct 24	Apr 22	Nov 15
2020	May 10	Oct 19	Apr 17	Oct 19
2019	Apr 16	Oct 25	Apr 12	Oct 26
2018	Apr 28	Oct 12	Apr 20	Nov 8
2017	Apr 28	Oct 28	Mar 22	Nov 6
2016	May 15	Nov 19	Apr 12	Nov 19
2015	Apr 23	Oct 17	Mar 28	Nov 20
2014	Apr 18	Oct 31	Apr 18	Nov 1
2013	May 3	Oct 20	Apr 24	Oct 22
2012	Apr 17	Oct 7	Mar 9	Oct 28
2011	May 3	Oct 21	Mar 30	Nov 4
2010	Apr 9	Oct 29	Mar 26	Oct 29
2009	Apr 11	Oct 10	Mar 29	Oct 11
2008	Apr 29	Oct 21	Apr 14	Oct 28
2007	Apr 14	Oct 28	Apr 10	Nov 7
2006	Apr 8	Oct 11	Apr 8	Oct 12
2005	May 3	Nov 10	May 3	Nov 10
2004	May 3	Oct 17	Apr 13	Nov 11
2003	Apr 9	Oct 2	Apr 9	Oct 2
2002	May 3	Oct 16	Apr 6	Oct 16
2001	Apr 18	Oct 7	Apr 16	Nov 20
2000	Apr 21	Sep 21	Apr 18	Nov 8
1999	Apr 11	Oct 4	Mar 26	Oct 22
1998	Apr 10	Nov 3	Mar 24	Nov 4
1997	May 13	Oct 22	Apr 17	Oct 27
1996	Apr 27	Oct 3	Apr 9	Oct 30
1995	Apr 13	Oct 16	Apr 10	Oct 30
1994	Apr 10	Nov 1	Apr 6	Nov 1
1993	Apr 21	Oct 2	Apr 5	Oct 31
1992	Apr 27	Sep 29	Apr 12	Oct 17
1991	Apr 20	Oct 7	Mar 30	Oct 19
1990	Apr 17	Oct 10	Apr 17	Nov 7
1989	May 6	Oct 3	May 6	Oct 4
1988	Apr 24	Oct 5	Apr 19	Oct 22
1987	Apr 5	Oct 3	Apr 4	Oct 11
1986	Apr 22	Nov 1	Apr 22	Nov 2
1985	Apr 9	no data	Apr 9	no data
1984	Apr 5	Sep 26	Mar 31	Sep 26
1983	Apr 21	Oct 12	Apr 21	Oct 29
1982	no data	Oct 20	no data	Oct 22
1981	May 10	Oct 2	May 10	Oct 2
1980	Apr 27	Oct 5	Apr 14	Oct 12
1979	May 4	Oct 5	May 3	Oct 7
1978	May 2	Oct 8	May 1	Oct 17
1977	Apr 8	Oct 13	Apr 6	Oct 13
1976	Apr 28	Oct 6	Mar 22	Oct 8
1975	Apr 22	Oct 2	Apr 21	Oct 29
1974	May 11	Sep 22	May 7	Oct 2
1973	May 17	Sep 20	May 2	Sep 20
1972	Apr 24	Sep 30	Apr 8	Oct 17
1971	Apr 24	Oct 31	Apr 6	Oct 31
1970	Apr 20	Oct 10	Apr 4	Nov 7
1969	Apr 6	Oct 17	Mar 31	Oct 22
1968	Apr 25	Oct 4	Apr 6	Nov 11
1967	May 4	Sep 29	May 3	Oct 28
1966	May 10	Oct 16	May 9	Nov 1
1965	Apr 28	Oct 13	Mar 30	Oct 28
1964	Apr 15	Oct 9	Apr 8	Oct 9
1963	May 1	Oct 29	Apr 18	Nov 2
1962	Apr 16	Oct 23	Apr 16	Oct 23
1961	May 2	Sep 28	Apr 16	Oct 20
1960	Apr 18	Oct 20	Apr 18	Oct 20
1959	Apr 22	Oct 17	Apr 13	Oct 17
1958	Apr 29	Nov 3	Apr 29	Nov 10
1957	Apr 15	Oct 11	Apr 14	Oct 25
1956	Apr 30	Oct 10	Apr 30	Nov 9
1955	Apr 7	Nov 2	Apr 7	Nov 3
1954	May 4	Oct 18	Apr 8	Oct 30
1953	May 13	no data	May 13	no data
1952	Apr 15	no data	Apr 15	no data

"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.