Decatur Ap, IL: frost dates by year

Last spring and first fall frost at NOAA station USW00003887, 2001 to 2024, measured from daily minimum temperatures.

Elevation 675 ft, 39.834, -88.866. Download the data (JSON), NOAA daily records

Summary at 32°F

	Last spring frost	First fall frost
Median	Apr 20	Oct 19
Earliest	Mar 23 (2017)	Oct 2 (2003)
Latest	May 21 (2002)	Nov 12 (2016)
Trend	0.6 days later per decade	4.1 days later per decade
Years with data	24	24

At 28°F (hard freeze) the median last spring date is Apr 2 and the median first fall date is Nov 4.

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
2024	Apr 25	Oct 17	Apr 6	Nov 26
2023	Apr 24	Oct 30	Apr 2	Oct 31
2022	Apr 19	Oct 18	Mar 28	Nov 13
2021	May 12	Nov 2	Apr 2	Nov 3
2020	May 9	Oct 5	Apr 16	Nov 2
2019	Apr 15	Oct 12	Apr 1	Oct 31
2018	Apr 30	Oct 16	Apr 29	Oct 21
2017	Mar 23	Oct 26	Mar 22	Oct 29
2016	Apr 13	Nov 12	Apr 9	Nov 20
2015	Apr 24	Oct 17	Mar 28	Nov 10
2014	Apr 23	Oct 23	Mar 30	Nov 2
2013	Apr 20	Oct 21	Apr 4	Oct 25
2012	Apr 12	Oct 7	Apr 11	Nov 14
2011	Apr 21	Oct 28	Mar 31	Nov 30
2010	Apr 18	Oct 22	Mar 26	Nov 3
2009	Apr 12	Nov 1	Mar 30	Nov 12
2008	Apr 15	Oct 28	Apr 2	Nov 9
2007	Apr 16	Oct 29	Apr 10	Nov 10
2006	Apr 9	Oct 12	Mar 26	Nov 2
2005	May 4	Oct 28	Mar 21	Nov 16
2004	Apr 14	Oct 3	Mar 22	Nov 9
2003	Apr 23	Oct 2	Apr 10	Oct 2
2002	May 21	Oct 13	Apr 6	Oct 14
2001	Apr 18	Oct 7	Apr 18	Nov 6

"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.