Last Frost Day

Frost history / Elk Rvr, ID

Elk Rvr, ID: frost dates by year

Last spring and first fall frost at NOAA station USC00102892, 1952 to 2011, measured from daily minimum temperatures.

Elevation 2,866 ft, 46.782, -116.180. Download the data (JSON), NOAA daily records

Summary at 32°F

Last spring frostFirst fall frost
MedianJun 2Sep 7
EarliestMay 4 (1988)Aug 6 (1969)
LatestJul 28 (1959)Oct 9 (2011)
Trend4.8 days earlier per decade3.3 days later per decade
Years with data4744

At 28°F (hard freeze) the median last spring date is May 13 and the median first fall date is Sep 25.

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 29Jul 14Jul 29Aug 131960197019801990200020101952: Jul 71953: Jun 21954: Jun 181955: Jul 21956: Jun 261958: May 131959: Jul 281960: Jun 81961: May 181962: Jul 81963: May 171964: Jun 281965: Jun 281966: Jun 51968: May 311969: Jul 151970: May 311971: Jul 71972: Jul 11973: Jun 161974: Jun 11975: Jun 281976: Jul 11977: May 301978: May 301979: Jun 71980: May 111981: May 121982: May 301983: May 221984: Jul 91985: Jun 241986: May 231987: Jun 21988: May 41989: Jun 171990: May 261993: May 91994: May 141995: Jun 71998: May 282005: Jun 142007: May 292008: Jun 112009: May 222010: May 242011: May 26

First fall frost (32°F)

Jul 29Aug 13Aug 28Sep 12Sep 27Oct 12Oct 271960197019801990200020101952: Aug 241953: Sep 171954: Sep 301955: Aug 271956: Sep 21957: Aug 151958: Sep 31959: Aug 301960: Aug 281961: Sep 61962: Sep 81963: Sep 181964: Sep 91965: Aug 301966: Sep 11967: Aug 251968: Sep 281969: Aug 61970: Sep 91971: Aug 241972: Sep 101973: Sep 11974: Aug 131975: Aug 251976: Aug 201977: Sep 231978: Sep 161979: Sep 121980: Aug 291981: Sep 231982: Sep 111983: Sep 101984: Aug 201985: Sep 71986: Sep 121987: Sep 171989: Sep 121990: Oct 61994: Sep 62004: Sep 212006: Sep 152007: Sep 202008: Sep 22011: Oct 9

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
2011May 26Oct 9May 4Oct 25
2010May 24no dataMay 21no data
2009May 22no dataMay 21no data
2008Jun 11Sep 2May 13Oct 8
2007May 29Sep 20May 6Sep 25
2006no dataSep 15no dataOct 8
2005Jun 14no dataMay 2no data
2004no dataSep 21no dataOct 25
1998May 28no dataApr 30no data
1995Jun 7no dataMay 15no data
1994May 14Sep 6May 1Oct 7
1993May 9no dataApr 28no data
1990May 26Oct 6May 9Oct 6
1989Jun 17Sep 12May 20Oct 3
1988May 4no dataMay 2no data
1987Jun 2Sep 17May 18Sep 18
1986May 23Sep 12May 17Oct 11
1985Jun 24Sep 7May 12Sep 21
1984Jul 9Aug 20Jul 9Sep 25
1983May 22Sep 10May 13Sep 20
1982May 30Sep 11May 5Sep 30
1981May 12Sep 23May 6Sep 24
1980May 11Aug 29Apr 4Oct 9
1979Jun 7Sep 12May 29Oct 3
1978May 30Sep 16May 30Sep 16
1977May 30Sep 23Apr 18Oct 4
1976Jul 1Aug 20May 1Oct 4
1975Jun 28Aug 25May 26Aug 26
1974Jun 1Aug 13May 31Sep 13
1973Jun 16Sep 1May 27Sep 16
1972Jul 1Sep 10May 4Sep 26
1971Jul 7Aug 24May 22Sep 14
1970May 31Sep 9May 14Sep 14
1969Jul 15Aug 6May 4Sep 6
1968May 31Sep 28May 31Oct 2
1967no dataAug 25no dataOct 15
1966Jun 5Sep 1May 23Oct 3
1965Jun 28Aug 30May 18Aug 30
1964Jun 28Sep 9May 25Sep 19
1963May 17Sep 18May 11Oct 20
1962Jul 8Sep 8May 5Sep 9
1961May 18Sep 6Apr 24Sep 24
1960Jun 8Aug 28May 23Sep 21
1959Jul 28Aug 30May 12Oct 1
1958May 13Sep 3May 13Sep 26
1957no dataAug 15no dataSep 19
1956Jun 26Sep 2May 14Sep 22
1955Jul 2Aug 27May 9Sep 22
1954Jun 18Sep 30May 14Sep 30
1953Jun 2Sep 17May 12Sep 18
1952Jul 7Aug 24Apr 29Oct 7

"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.