Boone, IA: frost dates by year

Last spring and first fall frost at NOAA station USC00130807, 1951 to 2025, measured from daily minimum temperatures.

Elevation 1,035 ft, 42.042, -93.891. Download the data (JSON) · NOAA daily records

Summary at 32°F

	Last spring frost	First fall frost
Median	May 1	Oct 6
Earliest	Apr 7 (1955)	Sep 12 (1975)
Latest	May 23 (1963)	Oct 29 (2010)
Trend	little change (less than half a day per decade)	0.8 days later per decade
Years with data	73	74

At 28°F (hard freeze) the median last spring date is Apr 18 and the median first fall date is Oct 15.

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