Greenfield, IA: frost dates by year

Last spring and first fall frost at NOAA station USC00133438, 1951 to 2025, measured from daily minimum temperatures.

Elevation 1,316 ft, 41.294, -94.446. Download the data (JSON), NOAA daily records

Summary at 32°F

	Last spring frost	First fall frost
Median	Apr 27	Oct 9
Earliest	Apr 4 (1987)	Sep 17 (1981)
Latest	May 22 (1963)	Nov 5 (1998)
Trend	1.4 days earlier per decade	0.7 days later per decade
Years with data	70	72

At 28°F (hard freeze) the median last spring date is Apr 13 and the median first fall date is Oct 22.

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