Last Frost Day

Frost history / Ft Atkinson, WI

Ft Atkinson, WI: frost dates by year

Last spring and first fall frost at NOAA station USC00472869, 1951 to 2025, measured from daily minimum temperatures.

Elevation 800 ft, 42.905, -88.859. Download the data (JSON) · NOAA daily records

Summary at 32°F

Last spring frostFirst fall frost
MedianMay 3Oct 7
EarliestApr 7 (1955)Sep 16 (1984)
LatestMay 29 (1984)Oct 29 (2017)
Trend1.1 days earlier per decade1.3 days later per decade
Years with data7473

At 28°F (hard freeze) the median last spring date is Apr 18 and the median first fall date is Oct 20.

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 1419601970198019902000201020201951: Apr 261952: Apr 151953: May 131954: May 71955: Apr 71956: May 81957: May 161958: May 231959: Apr 221960: May 131961: May 271962: Apr 201963: May 231964: May 141965: Apr 271966: May 101967: May 121968: May 51969: May 121970: May 61971: May 31972: Apr 261973: May 51974: May 71976: May 71977: May 101978: May 61979: May 11980: Apr 261981: May 191982: Apr 271983: May 101984: May 291985: Apr 101986: May 31987: May 51988: May 251989: May 121990: May 111991: Apr 221992: May 271993: Apr 271994: May 11995: Apr 251996: May 131997: May 231998: Apr 281999: Apr 262000: May 212001: Apr 182002: May 212003: Apr 232004: May 32005: May 42006: Apr 102007: Apr 162008: Apr 302009: Apr 172010: Apr 282011: Apr 212012: Apr 272013: May 132014: Apr 232015: Apr 262016: May 152017: May 32018: Apr 302019: Apr 292020: May 102021: May 112022: Apr 282023: Apr 282024: Apr 252025: Apr 17

First fall frost (32°F)

Aug 28Sep 12Sep 27Oct 12Oct 27Nov 1119601970198019902000201020201951: Sep 291952: Oct 31953: Oct 71954: Oct 191955: Oct 221956: Sep 201957: Sep 281958: Oct 11959: Oct 121960: Oct 181961: Sep 281962: Sep 291963: Oct 291964: Sep 281965: Oct 51966: Oct 61967: Oct 91968: Oct 41969: Oct 141970: Oct 161971: Oct 121972: Oct 91973: Oct 171975: Oct 21976: Sep 221977: Oct 131978: Oct 81979: Sep 221980: Oct 51981: Oct 21982: Oct 171983: Sep 221984: Sep 161985: Sep 301986: Oct 151987: Oct 31988: Oct 51989: Sep 241990: Oct 21991: Sep 201992: Sep 291993: Sep 301994: Oct 101995: Sep 231996: Oct 31997: Oct 151998: Oct 221999: Sep 212001: Oct 72002: Oct 142003: Oct 12004: Oct 32005: Oct 212006: Oct 122007: Oct 282008: Oct 42009: Oct 102010: Oct 42011: Oct 22012: Oct 82013: Oct 212014: Oct 112015: Oct 172016: Oct 142017: Oct 292018: Oct 132019: Oct 252020: Oct 52021: Oct 222022: Oct 82023: Oct 182024: Oct 162025: Oct 24

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
2025Apr 17Oct 24Apr 9Oct 24
2024Apr 25Oct 16Apr 7Nov 21
2023Apr 28Oct 18Apr 26Oct 30
2022Apr 28Oct 8Apr 17Oct 19
2021May 11Oct 22Apr 22Nov 3
2020May 10Oct 5May 9Oct 28
2019Apr 29Oct 25Apr 28Oct 30
2018Apr 30Oct 13Apr 30Oct 18
2017May 3Oct 29Apr 1Nov 6
2016May 15Oct 14Apr 12Nov 12
2015Apr 26Oct 17Apr 24Oct 17
2014Apr 23Oct 11Apr 16Oct 22
2013May 13Oct 21Apr 21Oct 22
2012Apr 27Oct 8Apr 11Oct 12
2011Apr 21Oct 2Apr 1Nov 4
2010Apr 28Oct 4Apr 9Oct 22
2009Apr 17Oct 10Apr 13Oct 10
2008Apr 30Oct 4Apr 3Oct 28
2007Apr 16Oct 28Apr 10Nov 7
2006Apr 10Oct 12Apr 9Oct 12
2005May 4Oct 21May 4Oct 27
2004May 3Oct 3May 3Oct 5
2003Apr 23Oct 1Apr 23Oct 2
2002May 21Oct 14Apr 7Oct 16
2001Apr 18Oct 7Mar 29Oct 7
2000May 21no dataMay 21no data
1999Apr 26Sep 21Mar 27Oct 24
1998Apr 28Oct 22Apr 27Oct 22
1997May 23Oct 15May 21Oct 15
1996May 13Oct 3Apr 17Oct 11
1995Apr 25Sep 23Apr 15Nov 3
1994May 1Oct 10Apr 8Nov 10
1993Apr 27Sep 30Apr 5Oct 10
1992May 27Sep 29Apr 28Oct 17
1991Apr 22Sep 20Apr 2Sep 27
1990May 11Oct 2Apr 18Oct 19
1989May 12Sep 24May 7Sep 24
1988May 25Oct 5Apr 22Oct 6
1987May 5Oct 3Apr 4Oct 3
1986May 3Oct 15Apr 22Nov 2
1985Apr 10Sep 30Apr 9Oct 26
1984May 29Sep 16Apr 8Sep 30
1983May 10Sep 22Apr 20Oct 14
1982Apr 27Oct 17Apr 10Oct 21
1981May 19Oct 2May 19Oct 3
1980Apr 26Oct 5Apr 25Oct 5
1979May 1Sep 22Apr 11Oct 13
1978May 6Oct 8May 1Oct 8
1977May 10Oct 13May 10Nov 11
1976May 7Sep 22Apr 13Sep 24
1975no dataOct 2no dataOct 2
1974May 7no dataApr 10no data
1973May 5Oct 17Apr 13Nov 5
1972Apr 26Oct 9Apr 25Oct 17
1971May 3Oct 12May 3Nov 4
1970May 6Oct 16May 6Oct 16
1969May 12Oct 14Apr 29Oct 15
1968May 5Oct 4Apr 6Oct 25
1967May 12Oct 9Apr 23Oct 12
1966May 10Oct 6May 10Oct 6
1965Apr 27Oct 5Apr 3Oct 28
1964May 14Sep 28Apr 15Oct 10
1963May 23Oct 29May 1Nov 2
1962Apr 20Sep 29Apr 20Oct 24
1961May 27Sep 28May 1Oct 2
1960May 13Oct 18Apr 18Oct 20
1959Apr 22Oct 12Apr 21Oct 28
1958May 23Oct 1Apr 29Nov 2
1957May 16Sep 28Apr 15Oct 20
1956May 8Sep 20Apr 30Oct 10
1955Apr 7Oct 22Mar 30Nov 3
1954May 7Oct 19May 7Oct 30
1953May 13Oct 7Apr 20Nov 4
1952Apr 15Oct 3Apr 11Oct 3
1951Apr 26Sep 29Apr 17Oct 31

"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.