Last Frost Day

Frost history / Boscobel Ap, WI

Boscobel Ap, WI: frost dates by year

Last spring and first fall frost at NOAA station USW00094994, 1999 to 2024, measured from daily minimum temperatures.

Elevation 672 ft, 43.156, -90.677. Download the data (JSON) · NOAA daily records

Summary at 32°F

Last spring frostFirst fall frost
MedianMay 12Oct 7
EarliestApr 16 (2007)Sep 15 (2007)
LatestMay 29 (2021)Oct 29 (2017)
Trend3.0 days later per decade6.4 days later per decade
Years with data2526

At 28°F (hard freeze) the median last spring date is Apr 21 and the median first fall date is Oct 18.

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)

Mar 31Apr 15Apr 30May 15May 30Jun 142000201020202000: May 152001: Apr 182002: May 212003: May 32004: May 52005: May 162006: May 62007: Apr 162008: May 122009: May 172010: Apr 282011: May 172012: Apr 272013: May 132014: Apr 232015: May 132016: May 152017: May 32018: Apr 292019: Apr 282020: May 122021: May 292022: May 232023: May 262024: Apr 25

First fall frost (32°F)

Aug 28Sep 12Sep 27Oct 12Oct 27Nov 112000201020201999: Sep 212000: Oct 62001: Sep 252002: Oct 72003: Sep 292004: Oct 22005: Oct 82006: Oct 112007: Sep 152008: Oct 32009: Oct 92010: Oct 32011: Oct 12012: Sep 182013: Oct 142014: Oct 52015: Oct 162016: Oct 132017: Oct 292018: Oct 122019: Oct 122020: Oct 42021: Oct 222022: Sep 282023: Oct 112024: Oct 14

Dots are single years. The gray line is the median, the green line the fitted trend.

Year by year

YearLast spring 32°FFirst fall 32°FLast spring 28°FFirst fall 28°F
2024Apr 25Oct 14Apr 21Oct 16
2023May 26Oct 11Apr 26Oct 30
2022May 23Sep 28Apr 17Oct 14
2021May 29Oct 22Apr 25Nov 2
2020May 12Oct 4May 12Oct 19
2019Apr 28Oct 12Apr 15Oct 25
2018Apr 29Oct 12Apr 29Oct 13
2017May 3Oct 29Apr 7Oct 29
2016May 15Oct 13May 15Nov 11
2015May 13Oct 16Apr 26Oct 17
2014Apr 23Oct 5Apr 18Oct 31
2013May 13Oct 14Apr 20Oct 21
2012Apr 27Sep 18Apr 12Oct 7
2011May 17Oct 1May 4Oct 21
2010Apr 28Oct 3Apr 9Oct 22
2009May 17Oct 9Apr 15Oct 10
2008May 12Oct 3Apr 14Oct 21
2007Apr 16Sep 15Apr 16Oct 25
2006May 6Oct 11Apr 9Oct 14
2005May 16Oct 8May 4Oct 21
2004May 5Oct 2May 3Oct 4
2003May 3Sep 29Apr 23Oct 1
2002May 21Oct 7May 3Oct 13
2001Apr 18Sep 25Apr 18Oct 6
2000May 15Oct 6Apr 25Oct 6
1999no dataSep 21no dataOct 14

"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 1991–2020 frost probabilities.