Denmark Wwtp, WI: frost dates by year

Last spring and first fall frost at NOAA station USC00472055, 2007 to 2025, measured from daily minimum temperatures.

Elevation 811 ft, 44.351, -87.812. Download the data (JSON), NOAA daily records

Summary at 32°F

	Last spring frost	First fall frost
Median	May 10	Oct 16
Earliest	Apr 23 (2009)	Oct 2 (2011)
Latest	May 28 (2008)	Oct 26 (2017)
Trend	5.1 days earlier per decade	5.5 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 28.

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 30	Oct 24	Apr 11	Nov 2
2024	Apr 26	Oct 16	Apr 25	Nov 26
2023	May 2	Oct 22	May 1	Oct 30
2022	May 5	Oct 8	Apr 28	Oct 27
2021	May 12	Oct 22	Apr 22	Nov 2
2020	May 13	Oct 16	May 12	Oct 19
2019	May 12	Oct 14	Apr 29	Oct 25
2018	Apr 30	Oct 13	Apr 29	Oct 13
2017	May 9	Oct 26	May 8	Oct 29
2016	May 15	Oct 13	Apr 12	Nov 12
2015	May 20	Oct 17	Apr 24	Oct 17
2014	May 16	Oct 19	Apr 23	Nov 2
2013	May 13	Oct 20	May 13	Oct 23
2012	Apr 29	Oct 11	Apr 29	Oct 12
2011	May 4	Oct 2	Apr 21	Oct 28
2010	May 10	Oct 22	Apr 22	Oct 29
2009	Apr 23	Oct 10	Apr 23	Oct 11
2008	May 28	Oct 3	Apr 29	Oct 29
2007	no data	Oct 12	no data	Oct 28

"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.