Pontiac, IL: frost dates by year

Last spring and first fall frost at NOAA station USC00116910, 1951 to 2016, measured from daily minimum temperatures.

Elevation 650 ft, 40.878, -88.636. Download the data (JSON), NOAA daily records

Summary at 32°F

	Last spring frost	First fall frost
Median	Apr 17	Oct 20
Earliest	Mar 25 (1998)	Sep 23 (1974)
Latest	May 12 (1981)	Nov 12 (2016)
Trend	1.3 days earlier per decade	0.9 days earlier per decade
Years with data	62	65

At 28°F (hard freeze) the median last spring date is Apr 8 and the median first fall date is Nov 1.

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