Last Frost Day

Frost history / Platteville, WI

Platteville, WI: frost dates by year

Last spring and first fall frost at NOAA station USC00476646, 1951 to 2010, measured from daily minimum temperatures.

Elevation 990 ft, 42.749, -90.466. Download the data (JSON), NOAA daily records

Summary at 32°F

Last spring frostFirst fall frost
MedianMay 6Oct 3
EarliestApr 5 (1987)Sep 11 (1955)
LatestMay 29 (1984)Oct 28 (1963)
Trend2.3 days earlier per decade1.6 days later per decade
Years with data5960

At 28°F (hard freeze) the median last spring date is Apr 19 and the median first fall date is Oct 16.

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 141960197019801990200020101951: Apr 261952: May 291953: May 131954: May 91955: Apr 81956: May 161957: May 51958: May 71959: Apr 221960: May 121961: May 261962: Apr 201963: May 231964: Apr 151965: May 291966: May 141967: May 201968: Apr 271969: May 121970: May 61971: May 271972: Apr 261973: May 171974: May 71975: Apr 221976: May 81977: May 91978: May 61979: May 11980: May 91981: May 121983: May 91984: May 291985: Apr 101986: May 31987: Apr 51988: May 251989: May 71990: May 111991: Apr 241992: May 271993: Apr 231994: May 21995: Apr 251996: May 21997: May 161998: Apr 181999: Apr 252000: Apr 222001: Apr 192002: May 212003: Apr 232004: May 42005: May 62006: Apr 102007: Apr 172008: Apr 292009: Apr 132010: May 9

First fall frost (32°F)

Aug 28Sep 12Sep 27Oct 12Oct 27Nov 111960197019801990200020101951: Sep 281952: Sep 231953: Sep 221954: Oct 71955: Sep 111956: Sep 201957: Sep 281958: Oct 11959: Sep 181960: Oct 181961: Sep 281962: Sep 201963: Oct 281964: Sep 281965: Oct 121966: Sep 301967: Sep 291968: Oct 41969: Oct 141970: Oct 101971: Oct 71972: Sep 301973: Oct 171974: Sep 221975: Sep 131976: Sep 221977: Oct 61978: Oct 81979: Oct 51980: Oct 41981: Sep 281982: Sep 211983: Sep 221984: Sep 161985: Oct 61986: Oct 61987: Oct 31988: Oct 41989: Sep 231990: Oct 111991: Sep 201992: Sep 291993: Sep 301994: Oct 101995: Sep 221996: Oct 31997: Oct 141998: Oct 141999: Oct 52000: Oct 62001: Sep 252002: Oct 72003: Sep 292004: Oct 22005: Oct 232006: Oct 122007: Sep 152008: Oct 212009: Oct 102010: Oct 22

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