Monmouth, IL: frost dates by year

Last spring and first fall frost at NOAA station USC00115768, 1951 to 2025, measured from daily minimum temperatures.

Elevation 720 ft, 40.944, -90.638. Download the data (JSON), NOAA daily records

Summary at 32°F

	Last spring frost	First fall frost
Median	Apr 21	Oct 12
Earliest	Mar 30 (1991)	Sep 20 (1956)
Latest	May 20 (1954)	Nov 11 (2016)
Trend	0.5 days earlier per decade	1.2 days later per decade
Years with data	73	71

At 28°F (hard freeze) the median last spring date is Apr 10 and the median first fall date is Oct 26.

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

"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.