Polo 5NW, IL: frost dates by year

Last spring and first fall frost at NOAA station USC00116897, 1995 to 2017, measured from daily minimum temperatures.

Elevation 856 ft, 42.034, -89.607. Download the data (JSON), NOAA daily records

Summary at 32°F

	Last spring frost	First fall frost
Median	Apr 30	Oct 5
Earliest	Apr 18 (2001)	Sep 15 (2007)
Latest	May 21 (2002)	Oct 16 (2005)
Trend	3.8 days later per decade	3.3 days later per decade
Years with data	22	22

At 28°F (hard freeze) the median last spring date is Apr 18 and the median first fall date is Oct 13.

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
2017	May 3	no data	Mar 22	no data
2016	May 15	Oct 13	Apr 12	Nov 12
2015	May 1	Oct 14	Apr 24	Oct 17
2014	Apr 23	Oct 10	Apr 23	Oct 11
2013	May 13	Oct 13	Apr 20	Oct 22
2012	Apr 27	Sep 23	Apr 12	Sep 24
2011	May 4	Oct 1	May 4	Oct 28
2010	May 9	Oct 4	Apr 18	Oct 4
2009	May 17	Oct 10	Apr 15	Oct 10
2008	Apr 29	Oct 4	Apr 14	Oct 21
2007	Apr 20	Sep 15	Apr 16	Oct 28
2006	Apr 26	Oct 6	Apr 26	Oct 12
2005	May 16	Oct 16	May 4	Oct 23
2004	May 3	Sep 29	May 3	Oct 5
2003	Apr 23	Sep 29	Apr 13	Oct 1
2002	May 21	Sep 24	Apr 6	Oct 16
2001	Apr 18	Oct 6	Apr 18	Oct 6
2000	Apr 25	Oct 6	Apr 12	Oct 7
1999	Apr 19	Sep 22	Mar 30	Oct 14
1998	Apr 19	Oct 13	Apr 17	Oct 22
1997	May 16	Oct 15	May 16	Oct 17
1996	Apr 27	Oct 3	Apr 27	Oct 10
1995	no data	Sep 22	no data	Sep 23

"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.