Berlin Wwtp, WI: frost dates by year

Last spring and first fall frost at NOAA station USC00470742, 2005 to 2025, measured from daily minimum temperatures.

Elevation 766 ft, 43.990, -88.941. Download the data (JSON), NOAA daily records

Summary at 32°F

	Last spring frost	First fall frost
Median	May 8	Oct 13
Earliest	Apr 14 (2007)	Sep 14 (2007)
Latest	May 27 (2023)	Oct 29 (2017)
Trend	3.7 days later per decade	9.5 days later per decade
Years with data	21	21

At 28°F (hard freeze) the median last spring date is Apr 21 and the median first fall date is Oct 22.

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 24	Apr 16	Oct 24
2024	Apr 25	Oct 16	Apr 21	Oct 16
2023	May 27	Oct 17	Apr 24	Oct 29
2022	May 4	Oct 7	Apr 27	Oct 15
2021	May 9	Oct 22	Apr 25	Oct 24
2020	May 13	Oct 2	May 12	Oct 19
2019	Apr 29	Oct 14	Apr 28	Oct 25
2018	Apr 30	Oct 13	Apr 30	Oct 18
2017	May 8	Oct 29	Apr 7	Oct 29
2016	May 15	Oct 25	May 15	Nov 20
2015	May 13	Oct 16	Apr 26	Oct 16
2014	May 17	Oct 9	Apr 16	Oct 22
2013	May 15	Oct 14	Apr 21	Oct 22
2012	Apr 29	Sep 19	Apr 27	Oct 12
2011	May 4	Oct 3	Apr 21	Oct 28
2010	May 9	Oct 3	Apr 10	Oct 29
2009	Apr 21	Sep 30	Apr 13	Oct 10
2008	May 19	Oct 3	Apr 14	Oct 21
2007	Apr 14	Sep 14	Apr 14	Oct 27
2006	May 7	Oct 5	Apr 8	Oct 11
2005	May 3	Oct 19	Apr 27	Oct 27

"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.