Last Frost Day

Frost history / Priest Rvr Exp Stn, ID

Priest Rvr Exp Stn, ID: frost dates by year

Last spring and first fall frost at NOAA station USC00107386, 1951 to 2024, measured from daily minimum temperatures.

Elevation 2,371 ft, 48.351, -116.835. Download the data (JSON), NOAA daily records

Summary at 32°F

Last spring frostFirst fall frost
MedianMay 24Sep 11
EarliestApr 17 (1980)Aug 18 (1973)
LatestJul 18 (1962)Oct 12 (2022)
Trend2.9 days earlier per decade0.7 days later per decade
Years with data7474

At 28°F (hard freeze) the median last spring date is May 10 and the median first fall date is Sep 22.

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 14Jul 2919601970198019902000201020201951: Jun 21952: Jul 61953: May 311954: Jun 181955: May 311956: Jun 301957: Jul 41958: May 141959: May 311960: Jun 181961: May 281962: Jul 181963: May 171964: Jun 281965: Jun 141966: May 231967: May 261968: May 161969: May 51970: May 181971: May 151972: May 51973: Jun 191974: May 171975: May 251976: Jun 41977: May 301978: May 301979: Jul 31980: Apr 171981: May 131982: May 111983: May 141984: Jun 21985: Jun 241986: May 231987: May 221988: May 151989: May 221990: May 101991: Jun 41992: May 221993: May 91994: May 171995: May 261996: Jun 191997: May 221998: May 281999: Jul 42000: Jun 12001: May 302002: Jun 72003: May 202004: Jun 12005: May 252006: May 142007: Jun 262008: May 102009: Jun 92010: May 242011: May 302012: Jun 92013: May 242014: May 132015: May 102016: May 12017: May 152018: May 22019: May 62020: May 52021: May 212022: May 232023: Apr 282024: Jun 17

First fall frost (32°F)

Aug 13Aug 28Sep 12Sep 27Oct 12Oct 2719601970198019902000201020201951: Sep 111952: Aug 301953: Sep 171954: Sep 291955: Sep 181956: Sep 21957: Aug 281958: Sep 201959: Aug 251960: Aug 201961: Sep 81962: Sep 31963: Sep 191964: Sep 101965: Aug 301966: Sep 301967: Aug 251968: Oct 21969: Aug 281970: Sep 91971: Sep 141972: Sep 101973: Aug 181974: Sep 131975: Sep 191976: Sep 71977: Sep 231978: Sep 171979: Sep 291980: Sep 241981: Sep 241982: Sep 151983: Sep 191984: Aug 291985: Sep 71986: Sep 121987: Sep 171988: Sep 81989: Sep 91990: Sep 201991: Sep 191992: Aug 241993: Sep 161994: Sep 121995: Sep 211996: Sep 221997: Oct 71998: Sep 211999: Sep 12000: Aug 282001: Sep 62002: Sep 42003: Sep 132004: Sep 202005: Sep 62006: Sep 12007: Sep 82008: Aug 312009: Sep 212010: Sep 22011: Sep 32012: Aug 252013: Sep 202014: Sep 112015: Sep 42016: Sep 42017: Sep 152018: Sep 182019: Sep 252020: Sep 82021: Aug 312022: Oct 122023: Oct 12024: Sep 21

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
2024Jun 17Sep 21May 3Sep 21
2023Apr 28Oct 1Apr 23Oct 27
2022May 23Oct 12May 12Oct 16
2021May 21Aug 31May 21Oct 8
2020May 5Sep 8Apr 28Sep 8
2019May 6Sep 25May 1Oct 1
2018May 2Sep 18Apr 24Sep 18
2017May 15Sep 15May 8Sep 16
2016May 1Sep 4Apr 5Sep 13
2015May 10Sep 4May 9Sep 27
2014May 13Sep 11May 12Sep 12
2013May 24Sep 20May 2Sep 27
2012Jun 9Aug 25May 12Sep 11
2011May 30Sep 3May 18Sep 3
2010May 24Sep 2May 24Oct 12
2009Jun 9Sep 21May 10Sep 21
2008May 10Aug 31May 9Oct 8
2007Jun 26Sep 8May 25Sep 20
2006May 14Sep 1May 13Sep 15
2005May 25Sep 6May 19Sep 21
2004Jun 1Sep 20May 14Oct 24
2003May 20Sep 13May 20Sep 13
2002Jun 7Sep 4May 16Sep 21
2001May 30Sep 6May 30Sep 8
2000Jun 1Aug 28May 8Sep 23
1999Jul 4Sep 1May 11Sep 1
1998May 28Sep 21Apr 28Oct 16
1997May 22Oct 7May 8Oct 8
1996Jun 19Sep 22May 10Sep 23
1995May 26Sep 21May 1Sep 21
1994May 17Sep 12Apr 29Oct 5
1993May 9Sep 16Apr 20Oct 9
1992May 22Aug 24May 16Sep 6
1991Jun 4Sep 19May 4Sep 22
1990May 10Sep 20May 7Oct 6
1989May 22Sep 9May 20Oct 2
1988May 15Sep 8May 1Oct 17
1987May 22Sep 17May 19Oct 5
1986May 23Sep 12May 16Sep 12
1985Jun 24Sep 7May 13Sep 22
1984Jun 2Aug 29May 4Sep 14
1983May 14Sep 19May 13Sep 19
1982May 11Sep 15May 5Sep 15
1981May 13Sep 24May 7Oct 13
1980Apr 17Sep 24Apr 13Oct 9
1979Jul 3Sep 29Apr 25Oct 3
1978May 30Sep 17Apr 24Oct 12
1977May 30Sep 23May 16Oct 3
1976Jun 4Sep 7May 19Sep 8
1975May 25Sep 19May 1Oct 23
1974May 17Sep 13May 2Sep 27
1973Jun 19Aug 18May 11Sep 16
1972May 5Sep 10May 1Sep 29
1971May 15Sep 14Apr 20Sep 14
1970May 18Sep 9May 12Sep 12
1969May 5Aug 28Apr 28Oct 12
1968May 16Oct 2May 11Oct 2
1967May 26Aug 25May 26Sep 23
1966May 23Sep 30May 18Oct 9
1965Jun 14Aug 30May 19Sep 16
1964Jun 28Sep 10May 25Sep 10
1963May 17Sep 19May 11Oct 19
1962Jul 18Sep 3May 5Sep 8
1961May 28Sep 8Apr 21Sep 12
1960Jun 18Aug 20May 23Sep 7
1959May 31Aug 25May 12Oct 1
1958May 14Sep 20Apr 29Sep 20
1957Jul 4Aug 28Apr 25Sep 19
1956Jun 30Sep 2May 13Sep 3
1955May 31Sep 18May 28Sep 22
1954Jun 18Sep 29May 6Sep 30
1953May 31Sep 17May 11Sep 20
1952Jul 6Aug 30Jun 13Sep 13
1951Jun 2Sep 11Jun 1Sep 26

"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.