Markesan, WI: frost dates by year

Last spring and first fall frost at NOAA station USC00475096, 2007 to 2025, measured from daily minimum temperatures.

Elevation 861 ft, 43.703, -88.999. Download the data (JSON), NOAA daily records

Summary at 32°F

	Last spring frost	First fall frost
Median	May 12	Oct 8
Earliest	Apr 27 (2012)	Sep 15 (2007)
Latest	May 29 (2021)	Oct 26 (2017)
Trend	7.3 days earlier per decade	9.9 days later per decade
Years with data	18	19

At 28°F (hard freeze) the median last spring date is Apr 26 and the median first fall date is Oct 17.

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	May 9	Oct 20	Apr 17	Oct 24
2024	Apr 27	Oct 16	Apr 27	Oct 16
2023	May 3	Oct 9	Apr 26	Oct 30
2022	May 4	Oct 8	Apr 28	Oct 8
2021	May 29	Oct 17	Apr 24	Oct 26
2020	May 13	Oct 2	May 12	Oct 17
2019	Apr 29	Oct 14	Apr 28	Oct 25
2018	Apr 30	Sep 29	Apr 30	Oct 13
2017	May 9	Oct 26	May 8	Oct 29
2016	May 18	Oct 14	May 15	Oct 25
2015	May 13	Oct 14	Apr 27	Oct 17
2014	May 17	Oct 5	Apr 24	Oct 9
2013	May 13	Oct 14	Apr 4	Oct 19
2012	Apr 27	Oct 8	Mar 10	Oct 12
2011	May 17	Oct 2	May 4	Oct 2
2010	May 10	Oct 3	Apr 18	Oct 19
2009	May 17	Sep 30	Apr 20	Oct 10
2008	May 28	Oct 3	Apr 15	Oct 4
2007	no data	Sep 15	no data	Oct 25

"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.