Last Frost Day

Frost history / Council, ID

Council, ID: frost dates by year

Last spring and first fall frost at NOAA station USC00102187, 1951 to 2025, measured from daily minimum temperatures.

Elevation 2,943 ft, 44.744, -116.433. Download the data (JSON), NOAA daily records

Summary at 32°F

Last spring frostFirst fall frost
MedianMay 22Sep 27
EarliestApr 22 (1952)Sep 2 (2008)
LatestJun 30 (1968)Oct 26 (1979)
Trendlittle change (less than half a day per decade)1.1 days later per decade
Years with data4644

At 28°F (hard freeze) the median last spring date is May 1 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)

Apr 15Apr 30May 15May 30Jun 14Jun 29Jul 1419601970198019902000201020201951: May 21952: Apr 221954: May 281955: Apr 281956: Jun 51957: Apr 281958: Apr 271959: Jun 101960: Jun 201961: May 181962: Jun 41963: Apr 241964: May 311965: May 181966: Jun 51968: Jun 301969: Apr 301970: Jun 11971: May 201972: May 91973: May 261974: May 211975: May 261976: Jun 261977: May 271978: May 261979: May 291980: Jun 31981: May 131982: Jun 81985: May 131986: May 221987: May 22008: May 132009: May 212010: May 252011: May 282012: Jun 72013: May 232016: May 112019: May 42020: May 82021: May 92023: Jun 202024: May 242025: May 21

First fall frost (32°F)

Aug 28Sep 12Sep 27Oct 12Oct 27Nov 1119601970198019902000201020201951: Oct 201952: Sep 141953: Sep 251954: Sep 121955: Sep 261956: Sep 211957: Oct 61958: Sep 201959: Sep 291961: Sep 221962: Sep 91963: Oct 201964: Sep 191965: Sep 171966: Oct 41967: Oct 41968: Oct 31969: Sep 41970: Sep 141971: Sep 181972: Sep 201973: Oct 31974: Sep 281975: Oct 81976: Oct 81977: Sep 221978: Sep 201979: Oct 261980: Oct 101981: Sep 241985: Sep 262007: Sep 242008: Sep 22010: Sep 62011: Oct 92012: Oct 42014: Sep 122016: Oct 42017: Oct 52020: Oct 152021: Oct 132022: Oct 162023: Oct 132024: Sep 30

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
2025May 21no dataMay 19no data
2024May 24Sep 30May 2Oct 30
2023Jun 20Oct 13Apr 21Oct 24
2022no dataOct 16no dataOct 23
2021May 9Oct 13Apr 12Oct 16
2020May 8Oct 15Apr 18Oct 23
2019May 4no dataMay 2no data
2017no dataOct 5no dataOct 8
2016May 11Oct 4Apr 5Oct 12
2014no dataSep 12no dataOct 27
2013May 23no dataMay 23no data
2012Jun 7Oct 4Apr 7Oct 4
2011May 28Oct 9May 5Oct 25
2010May 25Sep 6May 7Oct 13
2009May 21no dataMay 13no data
2008May 13Sep 2May 13Oct 13
2007no dataSep 24no dataSep 29
1987May 2no dataApr 9no data
1986May 22no dataMay 15no data
1985May 13Sep 26May 12Sep 29
1982Jun 8no dataMay 6no data
1981May 13Sep 24May 7Oct 4
1980Jun 3Oct 10Apr 8Oct 17
1979May 29Oct 26Apr 19Oct 30
1978May 26Sep 20Apr 13Sep 20
1977May 27Sep 22Apr 20Oct 8
1976Jun 26Oct 8Apr 23Oct 17
1975May 26Oct 8May 25Oct 23
1974May 21Sep 28May 18Oct 6
1973May 26Oct 3Apr 18Oct 4
1972May 9Sep 20May 1Sep 26
1971May 20Sep 18Apr 10Sep 19
1970Jun 1Sep 14Apr 23Sep 15
1969Apr 30Sep 4Apr 26Oct 5
1968Jun 30Oct 3May 7Oct 9
1967no dataOct 4no dataOct 15
1966Jun 5Oct 4May 23Oct 9
1965May 18Sep 17May 18Sep 17
1964May 31Sep 19May 31Oct 2
1963Apr 24Oct 20Apr 24Oct 26
1962Jun 4Sep 9Apr 30Oct 7
1961May 18Sep 22Apr 27Sep 22
1960Jun 20no dataMay 22no data
1959Jun 10Sep 29May 11Oct 17
1958Apr 27Sep 20Mar 27Sep 20
1957Apr 28Oct 6Apr 26Oct 29
1956Jun 5Sep 21May 12Sep 22
1955Apr 28Sep 26Apr 27Sep 27
1954May 28Sep 12May 27Sep 30
1953no dataSep 25no dataSep 29
1952Apr 22Sep 14Apr 4Oct 15
1951May 2Oct 20May 1Oct 21

"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.