Hillsboro, IL: frost dates by year

Last spring and first fall frost at NOAA station USC00114108, 1951 to 2025, measured from daily minimum temperatures.

Elevation 630 ft, 39.161, -89.492. Download the data (JSON), NOAA daily records

Summary at 32°F

	Last spring frost	First fall frost
Median	Apr 12	Oct 18
Earliest	Mar 20 (2005)	Sep 21 (1991)
Latest	May 12 (1960)	Nov 11 (2011)
Trend	1.7 days earlier per decade	1.0 days later per decade
Years with data	66	70

At 28°F (hard freeze) the median last spring date is Apr 5 and the median first fall date is Nov 2.

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