Last Frost Day

Frost history / Idaho Falls 16 Se, ID

Idaho Falls 16 Se, ID: frost dates by year

Last spring and first fall frost at NOAA station USC00104456, 1960 to 2025, measured from daily minimum temperatures.

Elevation 5,828 ft, 43.346, -111.785. Download the data (JSON), NOAA daily records

Summary at 32°F

Last spring frostFirst fall frost
MedianJun 21Sep 4
EarliestMay 11 (2015)Aug 3 (1962)
LatestJul 31 (1995)Oct 14 (2023)
Trend3.4 days earlier per decade4.5 days later per decade
Years with data5859

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

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 30May 15May 30Jun 14Jun 29Jul 14Jul 29Aug 1319601970198019902000201020201961: Jun 141962: Jul 311963: Jun 301965: Jun 281966: Jun 261967: May 311968: Jul 21969: Jun 301970: Jun 11971: Jun 301972: Jun 271973: Jun 201974: Jul 31976: Jun 261977: Jun 301978: Jun 261979: Jun 91980: May 281981: Jul 81982: Jun 91983: Jul 161984: Jul 11985: Jun 111986: Jul 61987: Jun 21988: Jul 71989: Jun 241990: Jun 131991: Jun 141992: Jun 41993: Jul 181994: Jul 71995: Jul 311997: Jul 31998: Jun 212000: Jun 182001: Jun 142002: Jun 102003: Jun 232004: Jun 212005: Jun 172006: May 312007: Jun 182008: Jun 132011: Jun 172012: Jun 272013: Jun 232014: Jun 182015: May 112016: May 312017: May 272018: Jun 132019: Jun 212020: Jun 92021: Jun 112022: May 242023: Jun 222025: May 21

First fall frost (32°F)

Jul 29Aug 13Aug 28Sep 12Sep 27Oct 12Oct 2719601970198019902000201020201960: Aug 221961: Sep 31962: Aug 31963: Oct 101964: Aug 201965: Aug 261966: Aug 211967: Aug 81968: Aug 291969: Aug 61970: Sep 91971: Aug 241972: Sep 121974: Sep 21975: Sep 21976: Aug 61979: Sep 111980: Aug 41981: Aug 311982: Sep 61983: Sep 101984: Sep 141986: Sep 151987: Aug 171988: Aug 221989: Aug 251990: Sep 171991: Sep 111992: Aug 241993: Aug 251995: Aug 91996: Aug 71998: Aug 241999: Sep 12000: Sep 92001: Sep 82002: Sep 192003: Sep 142004: Sep 42005: Sep 182006: Aug 312007: Sep 102008: Sep 72009: Sep 212010: Sep 22011: Sep 202012: Sep 122013: Sep 192014: Sep 42015: Sep 62016: Aug 242017: Sep 172018: Sep 252019: Sep 292020: Sep 12021: Sep 172022: Oct 122023: Oct 142024: 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
2025May 21no dataApr 19no data
2024no dataOct 1no dataOct 19
2023Jun 22Oct 14May 11Oct 26
2022May 24Oct 12May 23Oct 24
2021Jun 11Sep 17May 11Sep 29
2020Jun 9Sep 1May 20Sep 9
2019Jun 21Sep 29Jun 11Sep 30
2018Jun 13Sep 25May 3Sep 25
2017May 27Sep 17May 18Sep 23
2016May 31Aug 24May 11Sep 6
2015May 11Sep 6May 11Oct 23
2014Jun 18Sep 4May 13Sep 4
2013Jun 23Sep 19May 3Oct 5
2012Jun 27Sep 12Jun 7Sep 12
2011Jun 17Sep 20May 18Oct 18
2010no dataSep 2no dataSep 6
2009no dataSep 21no dataSep 21
2008Jun 13Sep 7May 13Oct 9
2007Jun 18Sep 10May 29Sep 10
2006May 31Aug 31May 10Aug 31
2005Jun 17Sep 18Jun 8Sep 18
2004Jun 21Sep 4May 30Sep 21
2003Jun 23Sep 14May 20Sep 14
2002Jun 10Sep 19May 12Sep 21
2001Jun 14Sep 8May 21Sep 8
2000Jun 18Sep 9Jun 18Sep 9
1999no dataSep 1no dataSep 12
1998Jun 21Aug 24Jun 5Oct 5
1997Jul 3no dataJun 24no data
1996no dataAug 7no dataSep 18
1995Jul 31Aug 9Jun 7Sep 20
1994Jul 7no dataJun 17no data
1993Jul 18Aug 25Jun 13Aug 26
1992Jun 4Aug 24May 12Aug 25
1991Jun 14Sep 11May 28Sep 15
1990Jun 13Sep 17May 16Sep 17
1989Jun 24Aug 25Jun 21Sep 4
1988Jul 7Aug 22Jul 7Aug 22
1987Jun 2Aug 17Jun 2Sep 17
1986Jul 6Sep 15May 23Sep 21
1985Jun 11no dataJun 3no data
1984Jul 1Sep 14Jun 2Sep 14
1983Jul 16Sep 10May 17Sep 10
1982Jun 9Sep 6Jun 5Sep 15
1981Jul 8Aug 31Jul 8Sep 3
1980May 28Aug 4Apr 17Aug 4
1979Jun 9Sep 11Jun 9Sep 11
1978Jun 26no dataJun 17no data
1977Jun 30no dataMay 30no data
1976Jun 26Aug 6Jun 26Aug 27
1975no dataSep 2no dataSep 4
1974Jul 3Sep 2May 31Sep 2
1973Jun 20no dataJun 19no data
1972Jun 27Sep 12May 28Sep 20
1971Jun 30Aug 24May 23Sep 15
1970Jun 1Sep 9May 31Sep 9
1969Jun 30Aug 6Jun 1Sep 15
1968Jul 2Aug 29May 23Aug 29
1967May 31Aug 8May 26Sep 13
1966Jun 26Aug 21Jun 25Aug 21
1965Jun 28Aug 26May 27Aug 30
1964no dataAug 20no dataAug 20
1963Jun 30Oct 10May 20Oct 24
1962Jul 31Aug 3Jun 7Aug 30
1961Jun 14Sep 3May 19Sep 3
1960no dataAug 22no dataAug 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.