Last Frost Day

Frost history / Bonesteel, SD

Bonesteel, SD: frost dates by year

Last spring and first fall frost at NOAA station USC00390778, 1956 to 2003, measured from daily minimum temperatures.

Elevation 1,985 ft, 43.078, -98.951. Download the data (JSON), NOAA daily records

Summary at 32°F

Last spring frostFirst fall frost
MedianMay 5Oct 3
EarliestApr 10 (2003)Sep 3 (1974)
LatestMay 28 (1965)Nov 4 (1998)
Trend1.6 days earlier per decade0.5 days later per decade
Years with data4244

At 28°F (hard freeze) the median last spring date is Apr 26 and the median first fall date is Oct 11.

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 14196019701980199020001957: Apr 171958: Apr 281960: May 11961: May 91962: Apr 171963: May 221964: May 131965: May 281966: May 131967: May 71968: May 211969: Apr 291970: May 21971: May 121972: May 71973: May 141974: May 151975: May 11976: May 71977: Apr 251978: May 21979: May 111980: May 81983: May 31986: Apr 231987: Apr 121988: Apr 281989: May 71990: May 111991: May 71992: May 261993: Apr 221994: Apr 301995: Apr 281996: Apr 271997: May 161998: Apr 181999: Apr 192000: May 132001: Apr 242002: May 252003: Apr 10

First fall frost (32°F)

Aug 28Sep 12Sep 27Oct 12Oct 27Nov 11196019701980199020001956: Oct 231957: Oct 241960: Sep 301961: Sep 141962: Oct 201963: Oct 281964: Sep 271965: Sep 171966: Oct 11967: Sep 271968: Oct 31969: Oct 81970: Sep 261971: Sep 191972: Sep 261973: Oct 41974: Sep 31975: Oct 11976: Sep 281977: Oct 91978: Oct 61979: Oct 91981: Sep 171982: Oct 201984: Sep 251985: Sep 241986: Oct 121987: Oct 71988: Oct 41989: Sep 231990: Oct 91991: Sep 191992: Sep 291993: Oct 91994: Oct 251995: Sep 221996: Oct 101997: Oct 141998: Nov 41999: Sep 302000: Oct 62001: Oct 62002: Oct 132003: Sep 20

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
2003Apr 10Sep 20Apr 10Oct 26
2002May 25Oct 13May 3Oct 14
2001Apr 24Oct 6Apr 23Oct 6
2000May 13Oct 6Apr 18Oct 6
1999Apr 19Sep 30Apr 18Oct 2
1998Apr 18Nov 4Apr 3Nov 6
1997May 16Oct 14Apr 18Oct 14
1996Apr 27Oct 10Apr 27Oct 18
1995Apr 28Sep 22Apr 27Sep 22
1994Apr 30Oct 25Apr 30Oct 25
1993Apr 22Oct 9Apr 21Oct 9
1992May 26Sep 29Apr 27Oct 16
1991May 7Sep 19Mar 30Oct 6
1990May 11Oct 9May 1Oct 12
1989May 7Sep 23May 7Sep 23
1988Apr 28Oct 4Apr 27Oct 27
1987Apr 12Oct 7Apr 5Oct 10
1986Apr 23Oct 12Apr 17Oct 13
1985no dataSep 24no dataOct 2
1984no dataSep 25no dataSep 27
1983May 3no dataMay 3no data
1982no dataOct 20no dataOct 21
1981no dataSep 17no dataOct 22
1980May 8no dataMay 8no data
1979May 11Oct 9May 4Oct 12
1978May 2Oct 6Apr 21Oct 6
1977Apr 25Oct 9Apr 7Oct 9
1976May 7Sep 28May 7Sep 28
1975May 1Oct 1Apr 20Oct 25
1974May 15Sep 3Apr 16Sep 13
1973May 14Oct 4Apr 27Oct 29
1972May 7Sep 26Apr 24Oct 17
1971May 12Sep 19Apr 13Oct 28
1970May 2Sep 26May 2Oct 9
1969Apr 29Oct 8Mar 31Oct 12
1968May 21Oct 3Apr 24Oct 4
1967May 7Sep 27May 7Oct 10
1966May 13Oct 1May 13Oct 5
1965May 28Sep 17Apr 28Sep 24
1964May 13Sep 27Apr 9Sep 27
1963May 22Oct 28May 22Oct 28
1962Apr 17Oct 20Apr 15Oct 23
1961May 9Sep 14May 1Oct 2
1960May 1Sep 30Apr 30Sep 30
1958Apr 28no dataApr 28no data
1957Apr 17Oct 24Apr 14Oct 24
1956no dataOct 23no dataNov 4

"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.