Last Frost Day

Frost history / Idaho Falls Fanning Fld, ID

Idaho Falls Fanning Fld, ID: frost dates by year

Last spring and first fall frost at NOAA station USW00024145, 1951 to 2024, measured from daily minimum temperatures.

Elevation 4,729 ft, 43.516, -112.067. Download the data (JSON), NOAA daily records

Summary at 32°F

Last spring frostFirst fall frost
MedianMay 25Sep 18
EarliestApr 17 (1980)Aug 25 (1992)
LatestJun 26 (1976)Oct 26 (2023)
Trend0.6 days later per decade1.1 days later per decade
Years with data6869

At 28°F (hard freeze) the median last spring date is May 6 and the median first fall date is Oct 3.

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 1419601970198019902000201020201951: Jun 21952: May 171953: May 251954: Jun 81955: Jun 11956: May 141957: Apr 291958: May 131959: May 291960: May 241961: May 151962: Jun 71963: Apr 291964: May 241965: May 271966: Jun 251967: May 261968: May 161969: May 11970: May 311971: May 171972: May 121973: May 271974: May 311975: May 261976: Jun 261977: May 301978: Jun 171979: Jun 81980: Apr 171981: Jun 151982: Jun 91983: May 171984: May 171985: May 141986: May 231987: Jun 21988: May 201989: May 251990: Jun 131991: May 281992: May 121993: May 91999: Jun 92000: Jun 202001: Jun 132002: Jun 102003: Jun 232004: May 252005: Jun 82006: May 302007: May 292008: May 132009: May 162010: Jun 182011: May 172012: Jun 72014: May 132015: May 112016: May 222017: May 252018: May 32019: Jun 222020: May 232021: May 122022: May 232023: May 112024: Jun 19

First fall frost (32°F)

Aug 13Aug 28Sep 12Sep 27Oct 12Oct 27Nov 1119601970198019902000201020201951: Sep 121952: Sep 141953: Oct 31954: Sep 191955: Sep 221956: Sep 221957: Sep 141958: Sep 251959: Sep 231960: Aug 291961: Sep 31962: Sep 81963: Oct 101964: Aug 301965: Aug 301966: Oct 11967: Sep 131968: Sep 211969: Oct 41970: Sep 141971: Sep 151972: Sep 211973: Sep 171974: Sep 131975: Sep 181976: Sep 81977: Sep 181978: Sep 191979: Sep 111980: Sep 221981: Sep 261982: Oct 21983: Sep 191984: Sep 241985: Sep 201986: Sep 201987: Sep 171988: Sep 121989: Sep 41990: Oct 61991: Sep 151992: Aug 251993: Aug 311998: Oct 41999: Sep 82000: Sep 72001: Sep 82002: Sep 212003: Sep 132004: Sep 42005: Sep 142006: Aug 312007: Sep 102008: Oct 82009: Sep 212010: Sep 62011: Oct 102012: Oct 32014: Sep 122015: Oct 122016: Sep 62017: Sep 232018: Sep 172019: Sep 302020: Sep 92021: Sep 292022: Oct 132023: Oct 262024: Oct 1

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 19Oct 1May 2Oct 19
2023May 11Oct 26Apr 20Oct 28
2022May 23Oct 13May 11Oct 27
2021May 12Sep 29May 11Sep 30
2020May 23Sep 9May 8Oct 22
2019Jun 22Sep 30May 10Oct 3
2018May 3Sep 17Apr 18Sep 26
2017May 25Sep 23Apr 16Oct 3
2016May 22Sep 6May 11Oct 12
2015May 11Oct 12Apr 17Oct 28
2014May 13Sep 12May 13Sep 12
2012Jun 7Oct 3May 6Oct 4
2011May 17Oct 10May 5Oct 19
2010Jun 18Sep 6May 8Oct 20
2009May 16Sep 21May 13Oct 2
2008May 13Oct 8May 13Oct 13
2007May 29Sep 10May 4Oct 28
2006May 30Aug 31May 10Oct 12
2005Jun 8Sep 14May 1Oct 5
2004May 25Sep 4Apr 29Oct 24
2003Jun 23Sep 13May 20Sep 14
2002Jun 10Sep 21May 10Sep 22
2001Jun 13Sep 8May 21Oct 5
2000Jun 20Sep 7Apr 30Sep 23
1999Jun 9Sep 8May 11Sep 27
1998no dataOct 4no dataOct 5
1993May 9Aug 31May 1Sep 14
1992May 12Aug 25Apr 24Aug 26
1991May 28Sep 15Apr 30Oct 4
1990Jun 13Oct 6May 10Oct 7
1989May 25Sep 4May 25Oct 16
1988May 20Sep 12May 3Sep 19
1987Jun 2Sep 17Apr 21Sep 27
1986May 23Sep 20May 23Sep 23
1985May 14Sep 20May 13Sep 20
1984May 17Sep 24Apr 30Sep 29
1983May 17Sep 19May 17Sep 19
1982Jun 9Oct 2May 6Oct 6
1981Jun 15Sep 26Apr 14Oct 1
1980Apr 17Sep 22Apr 17Oct 10
1979Jun 8Sep 11May 7Oct 4
1978Jun 17Sep 19May 31Sep 20
1977May 30Sep 18May 5Oct 2
1976Jun 26Sep 8Apr 27Oct 7
1975May 26Sep 18May 26Oct 9
1974May 31Sep 13May 16Oct 5
1973May 27Sep 17May 2Oct 3
1972May 12Sep 21May 2Sep 25
1971May 17Sep 15Apr 27Sep 18
1970May 31Sep 14May 14Sep 15
1969May 1Oct 4May 1Oct 4
1968May 16Sep 21May 7Oct 7
1967May 26Sep 13May 13Oct 4
1966Jun 25Oct 1May 23Oct 1
1965May 27Aug 30May 6Sep 17
1964May 24Aug 30Apr 23Sep 19
1963Apr 29Oct 10Apr 23Oct 24
1962Jun 7Sep 8Apr 30Sep 9
1961May 15Sep 3May 7Sep 22
1960May 24Aug 29May 24Oct 14
1959May 29Sep 23May 7Sep 29
1958May 13Sep 25Apr 30Oct 21
1957Apr 29Sep 14Apr 27Oct 5
1956May 14Sep 22May 14Sep 22
1955Jun 1Sep 22Apr 28Sep 30
1954Jun 8Sep 19May 2Sep 30
1953May 25Oct 3May 12Oct 3
1952May 17Sep 14Apr 22Oct 14
1951Jun 2Sep 12May 14Sep 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.