Last Frost Day

Frost history / Bayfield 6 N, WI

Bayfield 6 N, WI: frost dates by year

Last spring and first fall frost at NOAA station USC00470603, 1951 to 2004, measured from daily minimum temperatures.

Elevation 820 ft, 46.883, -90.817. Download the data (JSON), NOAA daily records

Summary at 32°F

Last spring frostFirst fall frost
MedianMay 20Oct 2
EarliestApr 28 (1965)Sep 9 (1975)
LatestJun 10 (1972)Oct 26 (1994)
Trendlittle change (less than half a day per decade)0.6 days later per decade
Years with data5049

At 28°F (hard freeze) the median last spring date is May 8 and the median first fall date is Oct 14.

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 29196019701980199020001951: May 131953: May 161954: May 201955: May 171956: May 241957: May 161958: May 231959: May 151961: May 261962: Jun 31963: May 231965: Apr 281966: May 131967: May 301968: May 191969: May 311970: May 61971: Jun 91972: Jun 101973: May 131974: May 131975: May 121976: May 241977: May 101978: May 211979: May 61980: May 91981: May 181982: Jun 31983: May 261984: May 291985: May 21986: Jun 21987: May 241988: May 251989: May 121990: May 301991: May 191993: Jun 51994: May 271995: May 21996: May 301997: May 151998: May 101999: May 92000: May 202001: May 122002: May 212003: May 232004: Jun 3

First fall frost (32°F)

Aug 28Sep 12Sep 27Oct 12Oct 27Nov 11196019701980199020001951: Oct 71952: Oct 21953: Oct 71954: Oct 51955: Oct 241956: Sep 211957: Sep 271958: Oct 11959: Sep 171960: Sep 291962: Sep 201966: Oct 121967: Sep 281968: Oct 51969: Oct 171970: Sep 281971: Oct 121972: Sep 221973: Sep 201974: Sep 231975: Sep 91976: Sep 221977: Oct 71978: Oct 81979: Oct 71980: Sep 261981: Oct 21982: Oct 171983: Oct 91984: Sep 291985: Sep 251987: Oct 31988: Oct 61989: Oct 31990: Oct 91991: Sep 271992: Sep 291993: Sep 301994: Oct 261995: Sep 231996: Oct 31997: Oct 141998: Oct 221999: Oct 32000: Oct 42001: Sep 252002: Oct 72003: Sep 292004: Sep 29

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
2004Jun 3Sep 29May 16Oct 4
2003May 23Sep 29May 3Oct 2
2002May 21Oct 7May 20Oct 13
2001May 12Sep 25Apr 18Oct 17
2000May 20Oct 4May 19Nov 12
1999May 9Oct 3Apr 25Oct 3
1998May 10Oct 22Apr 28Nov 12
1997May 15Oct 14May 13Oct 22
1996May 30Oct 3May 12Oct 8
1995May 2Sep 23Apr 26Oct 22
1994May 27Oct 26May 7Oct 31
1993Jun 5Sep 30Apr 27Oct 2
1992no dataSep 29no dataOct 18
1991May 19Sep 27Apr 22Sep 27
1990May 30Oct 9Apr 18Oct 9
1989May 12Oct 3May 7Oct 18
1988May 25Oct 6May 17Oct 13
1987May 24Oct 3Apr 23Oct 3
1986Jun 2no dataMay 20no data
1985May 2Sep 25Apr 28Oct 11
1984May 29Sep 29May 3Oct 29
1983May 26Oct 9May 17Oct 29
1982Jun 3Oct 17Apr 28Oct 22
1981May 18Oct 2May 18Oct 2
1980May 9Sep 26Apr 24Oct 5
1979May 6Oct 7May 1Oct 14
1978May 21Oct 8May 7Oct 14
1977May 10Oct 7May 9Oct 23
1976May 24Sep 22May 6Sep 24
1975May 12Sep 9May 4Oct 2
1974May 13Sep 23May 10Oct 3
1973May 13Sep 20May 5Oct 29
1972Jun 10Sep 22May 8Oct 9
1971Jun 9Oct 12May 9Oct 31
1970May 6Sep 28May 6Oct 11
1969May 31Oct 17May 31Oct 18
1968May 19Oct 5May 10Oct 5
1967May 30Sep 28May 22Sep 29
1966May 13Oct 12May 10Oct 17
1965Apr 28no dataApr 28no data
1963May 23no dataMay 11no data
1962Jun 3Sep 20May 10Oct 24
1961May 26no dataMay 26no data
1960no dataSep 29no dataOct 18
1959May 15Sep 17May 15Sep 17
1958May 23Oct 1May 5Oct 5
1957May 16Sep 27May 16Oct 25
1956May 24Sep 21May 16Nov 9
1955May 17Oct 24Apr 7Nov 2
1954May 20Oct 5May 8Oct 30
1953May 16Oct 7May 13Nov 5
1952no dataOct 2no dataOct 5
1951May 13Oct 7Apr 20Oct 27

"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.