Baldwin, WI: frost dates by year

Last spring and first fall frost at NOAA station USC00470486, 1973 to 2023, measured from daily minimum temperatures.

Elevation 1,100 ft, 44.963, -92.391. Download the data (JSON), NOAA daily records

Summary at 32°F

	Last spring frost	First fall frost
Median	May 6	Sep 30
Earliest	Apr 27 (2012)	Sep 10 (2020)
Latest	May 19 (2015)	Oct 20 (2013)
Trend	4.6 days earlier per decade	2.9 days later per decade
Years with data	14	15

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

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
2023	May 3	no data	May 3	no data
2022	Apr 29	Sep 28	Apr 28	Oct 8
2021	May 12	Oct 17	May 11	Oct 22
2020	May 13	Sep 10	May 12	Oct 2
2019	May 3	Oct 12	Apr 28	Oct 25
2018	Apr 29	Sep 29	Apr 28	Oct 12
2017	Apr 29	Oct 10	Apr 8	Oct 28
2016	May 15	Oct 9	May 15	Nov 12
2015	May 19	Oct 16	Apr 24	Oct 17
2014	May 4	Sep 13	Apr 18	Oct 10
2013	May 13	Oct 20	Apr 26	Oct 22
2012	Apr 27	Sep 23	Apr 12	Sep 23
2011	May 16	Sep 15	May 4	Oct 21
2010	May 9	Oct 3	May 9	Oct 22
2009	no data	Sep 30	no data	Oct 9
1973	no data	Sep 20	no data	Nov 4

"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.