Last Frost Day

Frost history / Willow Rsvr, WI

Willow Rsvr, WI: frost dates by year

Last spring and first fall frost at NOAA station USC00479236, 1951 to 2024, measured from daily minimum temperatures.

Elevation 1,532 ft, 45.709, -89.848. Download the data (JSON), NOAA daily records

Summary at 32°F

Last spring frostFirst fall frost
MedianMay 26Sep 23
EarliestApr 26 (2024)Aug 9 (1964)
LatestJun 21 (1963)Oct 25 (2017)
Trend3.2 days earlier per decade4.1 days later per decade
Years with data7064

At 28°F (hard freeze) the median last spring date is May 10 and the median first fall date is Oct 5.

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)

Apr 15Apr 30May 15May 30Jun 14Jun 2919601970198019902000201020201951: Jun 51952: May 211953: Jun 71955: May 301956: Jun 21957: Jun 21958: Jun 171959: May 241960: Jun 71961: May 301962: Jun 21963: Jun 211964: Jun 161965: Jun 141966: Jun 11967: May 221968: May 211969: May 251970: May 171971: May 281972: Jun 101973: May 301974: May 261975: May 161976: May 251977: Jun 91978: May 211979: May 261980: Jun 101981: May 311982: Jun 161983: May 271984: May 301986: Jun 171987: Jun 101988: May 251989: May 111990: May 301992: May 241993: May 291994: May 271995: May 71996: May 131997: May 181998: Apr 281999: May 92000: May 202001: Apr 272002: May 222003: May 222004: May 282005: May 132006: May 222007: May 172008: May 282009: May 312010: May 152011: May 272012: May 102013: May 242014: May 172015: May 222016: May 182018: May 122019: May 102020: May 142021: May 302022: Jun 42023: May 32024: Apr 26

First fall frost (32°F)

Jul 29Aug 13Aug 28Sep 12Sep 27Oct 12Oct 27Nov 1119601970198019902000201020201951: Sep 71952: Sep 241954: Sep 231955: Sep 121956: Sep 181957: Sep 51958: Aug 161959: Sep 111960: Sep 181961: Sep 161962: Sep 261963: Aug 181964: Aug 91965: Aug 291966: Sep 261967: Sep 101968: Oct 51969: Sep 181970: Oct 101971: Sep 171972: Sep 221973: Sep 201974: Sep 41975: Sep 91976: Sep 21977: Sep 301978: Sep 221979: Sep 81980: Sep 171981: Sep 201982: Sep 221986: Aug 291987: Aug 241988: Oct 31989: Sep 241991: Sep 271992: Sep 231993: Sep 51996: Oct 31997: Oct 141998: Oct 21999: Sep 212000: Oct 62001: Oct 62003: Sep 292005: Oct 72006: Sep 282007: Sep 152008: Oct 32009: Sep 302010: Oct 32011: Sep 162012: Sep 262014: Oct 92015: Sep 302016: Oct 92017: Oct 252018: Sep 222019: Oct 132020: Sep 182021: Oct 222022: Sep 282023: Oct 132024: Oct 7

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

"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.