Last Frost Day

Frost history / Winter, WI

Winter, WI: frost dates by year

Last spring and first fall frost at NOAA station USC00479304, 1951 to 2020, measured from daily minimum temperatures.

Elevation 1,355 ft, 45.799, -90.995. Download the data (JSON), NOAA daily records

Summary at 32°F

Last spring frostFirst fall frost
MedianMay 29Sep 20
EarliestApr 30 (1998)Aug 9 (1964)
LatestJun 21 (1992)Oct 12 (2019)
Trend2.6 days earlier per decade1.9 days later per decade
Years with data6361

At 28°F (hard freeze) the median last spring date is May 16 and the median first fall date is Sep 30.

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: May 131952: May 301953: Jun 71954: Jun 51955: May 301956: Jun 21957: Jun 21958: Jun 171959: May 241960: Jun 71961: Jun 151962: Jun 21963: Jun 211964: Jun 161965: May 301966: Jun 101967: May 291968: May 131969: Jun 131970: May 271971: Jun 91972: Jun 101973: May 301974: May 261975: May 161976: May 251977: Jun 91978: Jun 81979: May 281980: Jun 161981: May 311983: May 261987: Jun 101988: May 251989: May 271990: Jun 41991: May 181992: Jun 211993: Jun 51994: Jun 21995: May 181996: May 301997: May 221998: Apr 301999: May 92001: May 292002: May 212003: Jun 12005: May 162006: May 222007: May 172008: May 282010: May 152011: May 172012: May 162013: May 242014: May 182015: May 312016: May 202017: May 192018: May 122019: May 132020: May 31

First fall frost (32°F)

Jul 29Aug 13Aug 28Sep 12Sep 27Oct 12Oct 2719601970198019902000201020201951: Sep 291952: Sep 211953: Sep 131954: Sep 231955: Sep 111956: Sep 71957: Sep 51958: Sep 111959: Sep 111960: Sep 281961: Sep 151962: Sep 201964: Aug 91965: Aug 291966: Sep 151967: Aug 221968: Oct 51969: Sep 281970: Sep 231971: Sep 171972: Sep 221974: Sep 11975: Sep 91976: Aug 151977: Oct 31980: Sep 171981: Sep 181982: Sep 221983: Sep 231986: Sep 71987: Sep 251988: Sep 61990: Oct 21991: Sep 201992: Sep 111993: Sep 71994: Sep 21995: Sep 81996: Oct 31997: Sep 211998: Sep 211999: Sep 202000: Sep 232001: Sep 242003: Sep 202004: Aug 212005: Sep 292006: Sep 202007: Sep 152008: Sep 92009: Sep 302010: Sep 262011: Sep 152012: Sep 182013: Sep 162014: Sep 132015: Sep 302016: Oct 82017: Oct 102018: Sep 292019: Oct 12

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