Last Frost Day

Frost history / Wentworth 2.5 Wnw, SD

Wentworth 2.5 Wnw, SD: frost dates by year

Last spring and first fall frost at NOAA station USC00399042, 1951 to 2006, measured from daily minimum temperatures.

Elevation 1,722 ft, 44.008, -97.004. Download the data (JSON) · NOAA daily records

Summary at 32°F

Last spring frostFirst fall frost
MedianMay 7Sep 27
EarliestApr 14 (1985)Sep 11 (1955)
LatestMay 28 (1965)Oct 28 (1963)
Trend1.5 days earlier per decade0.7 days earlier per decade
Years with data5453

At 28°F (hard freeze) the median last spring date is Apr 28 and the median first fall date is Oct 9.

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 14196019701980199020001951: Apr 261953: May 141954: May 91955: May 81956: May 41957: May 51958: May 41959: May 151960: May 111961: May 91962: Apr 281963: May 221964: Apr 221965: May 281966: May 111967: May 201968: May 241969: May 121970: May 21971: May 131972: May 71973: May 141974: May 241975: May 11976: May 71977: Apr 251978: May 31979: May 111980: May 141981: May 111982: Apr 271983: May 151984: May 91985: Apr 141986: May 21987: Apr 211988: Apr 271989: May 61991: May 71992: Apr 271993: Apr 261994: May 11995: May 181996: May 31997: May 151998: Apr 281999: Apr 182000: Apr 212001: Apr 232002: May 242003: Apr 222004: May 142005: May 152006: May 5

First fall frost (32°F)

Aug 28Sep 12Sep 27Oct 12Oct 27Nov 11196019701980199020001951: Sep 221953: Oct 261954: Sep 221955: Sep 111956: Sep 301957: Oct 171958: Oct 11959: Sep 301960: Oct 191961: Sep 251962: Sep 201963: Oct 281964: Sep 131965: Sep 231966: Oct 51967: Sep 271968: Oct 31969: Oct 81970: Sep 261971: Sep 171972: Sep 291973: Oct 161974: Sep 221975: Oct 11976: Sep 231978: Oct 71979: Oct 41980: Sep 261981: Sep 171982: Sep 251983: Sep 211984: Sep 261985: Sep 241986: Oct 91987: Oct 31988: Oct 41989: Sep 231990: Sep 231991: Sep 191992: Sep 281993: Sep 271994: Oct 91995: Sep 221996: Oct 31997: Oct 131998: Oct 11999: Sep 292000: Sep 242001: Sep 242002: Sep 272003: Sep 192004: Oct 22005: 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
2006May 5no dataApr 8no data
2005May 15Oct 7May 3Oct 22
2004May 14Oct 2Apr 26Oct 2
2003Apr 22Sep 19Apr 9Sep 30
2002May 24Sep 27May 2Oct 9
2001Apr 23Sep 24Apr 17Oct 16
2000Apr 21Sep 24Apr 16Oct 6
1999Apr 18Sep 29Apr 18Oct 2
1998Apr 28Oct 1Apr 4Nov 3
1997May 15Oct 13May 15Oct 21
1996May 3Oct 3May 1Oct 23
1995May 18Sep 22Apr 13Sep 22
1994May 1Oct 9Apr 30Oct 25
1993Apr 26Sep 27Apr 7Oct 9
1992Apr 27Sep 28Apr 27Sep 28
1991May 7Sep 19Apr 10Sep 19
1990no dataSep 23no dataOct 9
1989May 6Sep 23May 6Sep 23
1988Apr 27Oct 4Apr 26Oct 4
1987Apr 21Oct 3Apr 21Oct 7
1986May 2Oct 9Apr 13Oct 13
1985Apr 14Sep 24Apr 9Sep 26
1984May 9Sep 26Apr 28Sep 26
1983May 15Sep 21Apr 18Oct 14
1982Apr 27Sep 25Apr 22Oct 20
1981May 11Sep 17May 10Oct 22
1980May 14Sep 26May 8Oct 3
1979May 11Oct 4May 3Oct 9
1978May 3Oct 7Apr 21Oct 7
1977Apr 25no dataApr 6no data
1976May 7Sep 23May 7Oct 6
1975May 1Oct 1Apr 20Oct 10
1974May 24Sep 22May 3Sep 22
1973May 14Oct 16May 14Oct 29
1972May 7Sep 29Apr 24Oct 15
1971May 13Sep 17May 12Oct 28
1970May 2Sep 26May 2Oct 9
1969May 12Oct 8Apr 6Oct 14
1968May 24Oct 3May 5Oct 4
1967May 20Sep 27May 4Oct 10
1966May 11Oct 5May 9Oct 16
1965May 28Sep 23Apr 28Sep 26
1964Apr 22Sep 13Apr 9Oct 9
1963May 22Oct 28May 22Oct 29
1962Apr 28Sep 20Apr 15Sep 20
1961May 9Sep 25May 2Sep 28
1960May 11Oct 19Apr 30Oct 19
1959May 15Sep 30May 15Oct 9
1958May 4Oct 1Apr 29Oct 11
1957May 5Oct 17May 5Oct 18
1956May 4Sep 30Apr 30Sep 30
1955May 8Sep 11May 8Oct 8
1954May 9Sep 22May 8Sep 22
1953May 14Oct 26May 13Oct 26
1951Apr 26Sep 22Apr 23Sep 24

"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 1991–2020 frost probabilities.