Last Frost Day

Frost history / Deer Flat Dam, ID

Deer Flat Dam, ID: frost dates by year

Last spring and first fall frost at NOAA station USC00102444, 1951 to 2013, measured from daily minimum temperatures.

Elevation 2,510 ft, 43.576, -116.748. Download the data (JSON), NOAA daily records

Summary at 32°F

Last spring frostFirst fall frost
MedianApr 30Oct 12
EarliestMar 23 (1994)Sep 14 (1970)
LatestJul 15 (1983)Nov 4 (2013)
Trend1.1 days earlier per decade1.5 days later per decade
Years with data5450

At 28°F (hard freeze) the median last spring date is Apr 14 and the median first fall date is Oct 24.

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 16Mar 31Apr 15Apr 30May 15May 30Jun 14Jun 29Jul 14Jul 291960197019801990200020101951: Apr 221952: Apr 111953: Apr 291954: May 21955: Apr 271956: Apr 91957: Apr 261958: Apr 271959: May 31960: May 221961: May 51962: May 131963: Apr 211964: May 61965: May 61966: May 231967: May 111968: May 71969: May 21970: May 121971: Apr 221972: May 11973: May 111974: May 181975: May 261976: Apr 211977: Apr 201978: May 251979: Apr 201980: Apr 121981: Apr 141982: May 51983: Jul 151984: May 71985: May 41986: Apr 301988: May 21989: May 191990: Mar 301991: Apr 271992: Apr 71993: Apr 131994: Mar 231995: Apr 151996: Apr 221997: May 21998: Apr 151999: Apr 162002: May 82009: May 132010: May 232011: Apr 292012: Apr 72013: Apr 23

First fall frost (32°F)

Aug 28Sep 12Sep 27Oct 12Oct 27Nov 111960197019801990200020101951: Oct 171952: Oct 141953: Oct 31954: Sep 301955: Sep 291956: Oct 151957: Oct 171958: Oct 201959: Oct 171960: Oct 131961: Sep 221962: Oct 171963: Oct 261964: Oct 171965: Sep 171966: Oct 101967: Oct 151968: Oct 31969: Oct 51970: Sep 141971: Sep 191972: Sep 251973: Oct 41974: Oct 61975: Oct 231976: Oct 191977: Oct 81978: Oct 131979: Oct 271980: Oct 171981: Oct 41982: Oct 101983: Sep 211984: Sep 241986: Oct 111987: Sep 271988: Oct 301989: Oct 161990: Oct 71992: Sep 141993: Oct 271994: Oct 231995: Oct 51996: Oct 171998: Oct 192009: Oct 12010: Oct 272011: Oct 262012: Oct 72013: Nov 4

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
2013Apr 23Nov 4Mar 23Nov 5
2012Apr 7Oct 7Apr 7Nov 10
2011Apr 29Oct 26Apr 26Oct 27
2010May 23Oct 27May 4Nov 9
2009May 13Oct 1Apr 1Oct 29
2002May 8no dataApr 24no data
1999Apr 16no dataApr 11no data
1998Apr 15Oct 19Mar 18Nov 2
1997May 2no dataApr 13no data
1996Apr 22Oct 17Mar 25Oct 17
1995Apr 15Oct 5Apr 15Oct 31
1994Mar 23Oct 23Mar 23Oct 30
1993Apr 13Oct 27Mar 6Oct 30
1992Apr 7Sep 14Apr 7Nov 10
1991Apr 27no dataApr 13no data
1990Mar 30Oct 7Mar 25Oct 17
1989May 19Oct 16Mar 30Oct 16
1988May 2Oct 30Apr 9Nov 15
1987no dataSep 27no dataOct 18
1986Apr 30Oct 11Apr 30Oct 11
1985May 4no dataApr 20no data
1984May 7Sep 24Apr 28Sep 24
1983Jul 15Sep 21Apr 14Nov 21
1982May 5Oct 10Apr 20Oct 19
1981Apr 14Oct 4Apr 14Oct 4
1980Apr 12Oct 17Apr 2Oct 23
1979Apr 20Oct 27Apr 3Nov 8
1978May 25Oct 13Mar 16Oct 23
1977Apr 20Oct 8Apr 20Nov 3
1976Apr 21Oct 19Apr 17Oct 19
1975May 26Oct 23May 25Oct 24
1974May 18Oct 6May 16Oct 6
1973May 11Oct 4Apr 8Oct 4
1972May 1Sep 25Apr 30Oct 27
1971Apr 22Sep 19Apr 8Oct 15
1970May 12Sep 14Apr 21Oct 15
1969May 2Oct 5Mar 25Oct 13
1968May 7Oct 3Apr 20Oct 21
1967May 11Oct 15Apr 21Oct 24
1966May 23Oct 10Apr 20Oct 14
1965May 6Sep 17Mar 28Sep 18
1964May 6Oct 17Apr 23Oct 17
1963Apr 21Oct 26Apr 21Oct 26
1962May 13Oct 17Apr 29Nov 7
1961May 5Sep 22Apr 20Oct 21
1960May 22Oct 13May 22Oct 13
1959May 3Oct 17Apr 10Oct 31
1958Apr 27Oct 20Mar 31Oct 21
1957Apr 26Oct 17Mar 27Nov 1
1956Apr 9Oct 15Apr 6Oct 28
1955Apr 27Sep 29Apr 12Nov 2
1954May 2Sep 30May 2Oct 1
1953Apr 29Oct 3Apr 15Nov 19
1952Apr 11Oct 14Apr 10Oct 28
1951Apr 22Oct 17Apr 22Oct 28

"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.