Last Frost Day

Frost history / Castleford 2 N, ID

Castleford 2 N, ID: frost dates by year

Last spring and first fall frost at NOAA station USC00101551, 1963 to 2018, measured from daily minimum temperatures.

Elevation 3,825 ft, 42.550, -114.866. Download the data (JSON), NOAA daily records

Summary at 32°F

Last spring frostFirst fall frost
MedianMay 16Sep 23
EarliestApr 12 (1994)Sep 3 (1964)
LatestJun 25 (1966)Nov 3 (2015)
Trend3.1 days earlier per decade4.3 days later per decade
Years with data4845

At 28°F (hard freeze) the median last spring date is Apr 30 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 14Jun 29Jul 14197019801990200020101965: May 61966: Jun 251968: May 161969: May 201970: May 171971: May 211972: May 91973: Jun 191974: May 171975: May 251976: Apr 301977: May 281978: May 311979: Jun 81980: Jun 31981: May 131982: May 291983: May 141984: May 161985: May 151986: May 231987: Apr 211988: May 41989: May 191990: May 161991: May 281992: Apr 241993: May 101994: Apr 121995: Jun 71996: Apr 291997: May 31998: May 271999: Jun 92000: May 122001: May 32002: May 92003: May 202005: Apr 292006: May 132007: May 232008: May 132009: May 132011: Jun 32012: May 82016: May 112017: May 172018: Apr 19

First fall frost (32°F)

Aug 28Sep 12Sep 27Oct 12Oct 27Nov 11197019801990200020101963: Oct 201964: Sep 31966: Oct 41967: Sep 141968: Sep 221969: Oct 31970: Sep 101971: Sep 161972: Sep 121973: Oct 31974: Sep 121976: Sep 91977: Sep 231978: Sep 191979: Oct 221980: Sep 221981: Sep 221982: Oct 61983: Sep 101984: Sep 221985: Sep 101986: Sep 211987: Sep 171988: Sep 191989: Sep 111990: Oct 71991: Oct 51992: Sep 71993: Sep 221994: Oct 191995: Sep 221997: Oct 51998: Oct 111999: Sep 112005: Oct 52006: Oct 142007: Sep 302008: Oct 102009: Oct 12010: Oct 132011: Oct 182012: Oct 42015: Nov 32017: Oct 32018: 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
2018Apr 19Oct 12Apr 19Oct 14
2017May 17Oct 3Apr 17Oct 3
2016May 11no dataMar 27no data
2015no dataNov 3no dataNov 7
2012May 8Oct 4Apr 9Oct 4
2011Jun 3Oct 18Apr 27Oct 26
2010no dataOct 13no dataNov 9
2009May 13Oct 1Apr 30Oct 2
2008May 13Oct 10May 10Oct 11
2007May 23Sep 30Apr 20Oct 27
2006May 13Oct 14May 3Oct 21
2005Apr 29Oct 5Apr 15Oct 5
2003May 20no dataMay 19no data
2002May 9no dataMay 9no data
2001May 3no dataApr 15no data
2000May 12no dataApr 30no data
1999Jun 9Sep 11May 11Sep 28
1998May 27Oct 11Apr 18Oct 19
1997May 3Oct 5May 2Oct 25
1996Apr 29no dataApr 21no data
1995Jun 7Sep 22Apr 16Sep 22
1994Apr 12Oct 19Apr 8Oct 23
1993May 10Sep 22Apr 20Oct 26
1992Apr 24Sep 7Apr 24Oct 7
1991May 28Oct 5Apr 30Oct 24
1990May 16Oct 7May 1Oct 7
1989May 19Sep 11Apr 26Oct 16
1988May 4Sep 19May 2Nov 7
1987Apr 21Sep 17Apr 20Oct 11
1986May 23Sep 21May 12Oct 11
1985May 15Sep 10May 15Sep 19
1984May 16Sep 22May 7Sep 25
1983May 14Sep 10May 13Sep 21
1982May 29Oct 6May 5Oct 9
1981May 13Sep 22Apr 14Oct 1
1980Jun 3Sep 22Apr 12Oct 23
1979Jun 8Oct 22May 29Oct 27
1978May 31Sep 19Apr 23Oct 13
1977May 28Sep 23May 5Oct 31
1976Apr 30Sep 9Apr 27Oct 19
1975May 25no dataMay 25no data
1974May 17Sep 12May 16Oct 6
1973Jun 19Oct 3May 11Oct 4
1972May 9Sep 12May 1Sep 24
1971May 21Sep 16Apr 16Sep 17
1970May 17Sep 10May 11Sep 16
1969May 20Oct 3Apr 30Oct 4
1968May 16Sep 22May 8Oct 3
1967no dataSep 14no dataOct 15
1966Jun 25Oct 4May 23Oct 4
1965May 6no dataMay 6no data
1964no dataSep 3no dataSep 27
1963no dataOct 20no dataOct 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 to 2020 frost probabilities.