Allison, IA: frost dates by year

Last spring and first fall frost at NOAA station USC00130157, 1951 to 2025, measured from daily minimum temperatures.

Elevation 1,038 ft, 42.754, -92.802. Download the data (JSON), NOAA daily records

Summary at 32°F

	Last spring frost	First fall frost
Median	Apr 30	Oct 8
Earliest	Apr 5 (1987)	Sep 20 (1991)
Latest	May 22 (1963)	Oct 30 (1973)
Trend	1.4 days earlier per decade	0.5 days later per decade
Years with data	70	73

At 28°F (hard freeze) the median last spring date is Apr 16 and the median first fall date is Oct 17.

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 15	Oct 23	Apr 8	Nov 9
2024	Apr 21	Oct 15	Apr 21	Oct 15
2023	May 2	Oct 10	Apr 24	Oct 28
2022	Apr 27	Oct 8	Apr 27	Oct 15
2021	Apr 26	Oct 22	Apr 23	Nov 1
2020	May 9	Oct 2	Apr 22	Oct 24
2019	Apr 29	Oct 12	Apr 16	Oct 12
2018	Apr 21	Oct 12	Apr 21	Oct 15
2017	Apr 29	Oct 27	Apr 29	Oct 29
2016	May 16	Oct 13	Apr 13	Nov 12
2015	Apr 24	Oct 16	Apr 24	Oct 17
2014	Apr 19	Oct 11	Apr 19	Oct 30
2013	May 13	Oct 15	Apr 26	Oct 23
2012	Apr 13	Sep 23	Apr 13	Oct 6
2011	May 3	Oct 20	Apr 6	Oct 21
2010	May 10	Oct 29	Mar 29	Oct 29
2009	Apr 21	Oct 10	Apr 11	Oct 11
2008	Apr 30	Oct 16	Apr 29	Oct 28
2007	Apr 15	Oct 23	Apr 14	Nov 7
2006	Apr 9	Oct 12	Apr 8	Oct 12
2005	May 4	Oct 8	May 3	Nov 10
2004	May 3	Oct 2	Apr 13	Oct 17
2003	Apr 10	Sep 30	Apr 10	Oct 2
2002	Apr 26	Oct 7	Apr 26	Oct 13
2001	no data	Oct 6	no data	Oct 17
2000	Apr 21	Oct 6	Apr 12	Oct 6
1999	Apr 18	Oct 4	Mar 27	Oct 4
1998	Apr 17	Oct 7	Mar 24	Oct 7
1997	May 15	Oct 14	Apr 17	Oct 21
1996	Apr 30	Oct 3	Apr 23	Oct 19
1995	Apr 19	no data	Apr 5	no data
1994	May 1	Oct 10	Apr 7	Oct 26
1993	Apr 21	Oct 2	Apr 17	Oct 10
1992	Apr 28	Sep 29	Apr 13	Oct 17
1991	Apr 10	Sep 20	Apr 10	Oct 7
1990	May 1	Oct 10	Apr 18	Oct 19
1989	May 7	Sep 23	May 6	Oct 4
1988	Apr 24	Oct 4	Apr 19	Oct 5
1987	Apr 5	Oct 3	Apr 4	Oct 8
1986	Apr 22	Oct 6	Apr 22	Nov 2
1985	Apr 15	Sep 27	Apr 9	Nov 4
1984	Apr 30	Sep 26	Mar 31	Sep 26
1983	May 15	Sep 23	Apr 20	Oct 13
1982	Apr 29	Oct 16	Apr 21	Oct 21
1981	May 11	Oct 2	May 10	Oct 2
1980	Apr 24	Sep 26	Apr 16	Oct 5
1979	no data	Oct 5	no data	Oct 13
1978	May 2	Oct 8	Mar 29	Oct 8
1977	no data	Oct 3	no data	Oct 13
1976	May 4	no data	Apr 12	no data
1975	Apr 22	Oct 2	Apr 4	Oct 2
1974	May 6	Sep 22	Apr 8	Oct 2
1973	May 3	Oct 30	Apr 13	Nov 4
1972	no data	Sep 30	no data	Oct 15
1971	May 12	Oct 28	Apr 24	Nov 6
1970	May 2	Oct 10	May 2	Oct 10
1969	May 12	Oct 14	Apr 1	Oct 14
1968	May 5	Oct 4	Apr 24	Oct 25
1967	no data	Sep 28	no data	Sep 28
1966	May 11	Oct 1	May 9	Oct 24
1965	Apr 28	Oct 12	Mar 31	Oct 24
1964	Apr 10	Oct 9	Apr 9	Oct 9
1963	May 22	Oct 28	Apr 4	Oct 29
1962	May 2	Oct 23	Apr 16	Oct 24
1961	May 3	Sep 28	May 1	Oct 20
1960	May 1	Oct 19	Apr 10	Oct 19
1959	Apr 22	Oct 11	Apr 13	Oct 12
1958	May 5	Oct 1	Apr 29	Oct 29
1957	May 4	Oct 10	Apr 14	Oct 25
1956	May 16	Oct 9	Apr 30	Nov 9
1955	May 8	Oct 15	Mar 29	Oct 24
1954	May 8	Oct 17	May 7	Oct 18
1953	May 13	Oct 26	May 13	Oct 27
1952	Apr 24	Oct 3	Apr 11	Oct 5
1951	Apr 26	Sep 28	Apr 19	Oct 27

"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.