Last Frost Day

Frost history / Ellsworth 1E, WI

Ellsworth 1E, WI: frost dates by year

Last spring and first fall frost at NOAA station USC00472556, 1951 to 2025, measured from daily minimum temperatures.

Elevation 1,030 ft, 44.730, -92.459. Download the data (JSON), NOAA daily records

Summary at 32°F

Last spring frostFirst fall frost
MedianMay 6Oct 2
EarliestApr 8 (1977)Sep 13 (1985)
LatestMay 29 (1965)Oct 30 (1973)
Trend0.5 days later per decadelittle change (less than half a day per decade)
Years with data6965

At 28°F (hard freeze) the median last spring date is Apr 26 and the median first fall date is Oct 17.

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 241953: May 131954: May 81957: May 41958: May 11959: May 151960: May 111961: May 21962: Apr 201963: May 221964: Apr 251965: May 291966: May 111967: May 51968: Apr 251969: May 121970: May 21971: May 21972: Apr 251973: May 31974: May 61975: Apr 271976: May 71977: Apr 81978: May 11981: May 191982: Apr 291983: May 261984: May 81985: Apr 151986: May 211987: May 71988: May 251990: May 111991: May 31992: May 61993: May 161994: May 61995: May 21996: May 131997: May 211998: Apr 281999: Apr 242000: May 192001: Apr 182002: May 212003: May 32004: May 152005: May 162006: May 62007: Apr 162008: May 122009: May 112010: May 92011: May 42012: Apr 272013: May 132015: May 192016: May 152017: Apr 292018: Apr 302019: May 202020: May 132021: May 132022: May 52023: May 32024: Apr 252025: May 1

First fall frost (32°F)

Aug 28Sep 12Sep 27Oct 12Oct 27Nov 1119601970198019902000201020201951: Sep 281952: Oct 31953: Sep 221954: Oct 71956: Oct 91957: Oct 101958: Oct 11959: Oct 91960: Oct 191961: Sep 281962: Oct 231963: Oct 291964: Sep 151965: Sep 261966: Oct 11967: Sep 281968: Oct 41969: Oct 131970: Oct 101972: Sep 301973: Oct 301974: Sep 221975: Oct 21976: Sep 231977: Oct 101981: Sep 281982: Sep 211983: Sep 231984: Sep 161985: Sep 131986: Oct 61987: Sep 251989: Sep 231991: Sep 201992: Sep 291993: Sep 301994: Oct 101995: Sep 221996: Oct 31997: Oct 141999: Sep 212000: Sep 242002: Sep 242004: Oct 22005: Oct 82006: Oct 102007: Sep 152008: Oct 42009: Sep 302010: Oct 32011: Sep 152012: Sep 232013: Oct 142014: Sep 132015: Oct 102016: Oct 92017: Oct 172018: Oct 112019: Oct 122020: Oct 22021: Oct 222022: Sep 282023: Oct 172024: Oct 162025: Oct 8

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

"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.