Last Frost Day

Frost history / Grace, ID

Grace, ID: frost dates by year

Last spring and first fall frost at NOAA station USC00103732, 1951 to 2025, measured from daily minimum temperatures.

Elevation 5,550 ft, 42.587, -111.728. Download the data (JSON), NOAA daily records

Summary at 32°F

Last spring frostFirst fall frost
MedianJun 9Sep 13
EarliestMay 3 (2018)Aug 16 (2009)
LatestJul 13 (1993)Oct 18 (2024)
Trend1.2 days earlier per decade1.5 days later per decade
Years with data7070

At 28°F (hard freeze) the median last spring date is May 16 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)

Apr 15Apr 30May 15May 30Jun 14Jun 29Jul 14Jul 2919601970198019902000201020201951: Jun 231952: Jun 161953: May 291954: Jun 291955: Jun 21956: Jun 221957: May 221958: May 131959: Jun 11960: Jun 211961: May 191962: Jun 71963: Jun 301965: May 271966: Jun 251967: May 261968: Jun 301969: Jun 301970: May 311971: May 211972: May 261973: Jun 191974: Jun 11975: May 291976: Jun 271977: May 301979: Jun 81980: Jun 71981: Jun 151984: Jun 121986: Jul 71987: Jun 21988: May 201989: Jun 211990: Jun 151991: Jun 151992: May 121993: Jul 131994: Jun 71995: Jun 221996: May 211997: Jun 251998: Jun 51999: Jun 92000: Jun 172001: Jun 142002: Jun 112003: May 202004: Jun 12005: Jun 132006: May 312007: Jun 262008: Jun 112009: May 222010: Jun 182011: Jun 172012: Jun 132013: Jun 42014: Jun 192015: May 112016: May 122017: May 182018: May 32019: Jun 202020: Jun 92021: Jun 112022: Jun 152023: May 92024: Jun 192025: May 6

First fall frost (32°F)

Jul 29Aug 13Aug 28Sep 12Sep 27Oct 12Oct 2719601970198019902000201020201951: Sep 121952: Sep 141953: Sep 181954: Sep 161955: Sep 221956: Sep 51957: Sep 111958: Sep 161959: Sep 91960: Aug 281961: Sep 141963: Oct 101965: Aug 301966: Aug 221967: Sep 131968: Sep 171969: Sep 221970: Sep 91971: Sep 151972: Sep 121973: Sep 21974: Sep 21975: Aug 251976: Aug 271977: Sep 91978: Aug 181979: Sep 111980: Sep 221981: Sep 201982: Sep 151983: Sep 101984: Sep 221987: Sep 171988: Aug 221989: Aug 251990: Oct 31991: Sep 151992: Aug 241993: Aug 261994: Sep 51995: Sep 211996: Aug 191997: Sep 271998: Oct 41999: Sep 82000: Sep 72001: Sep 82002: Sep 222003: Sep 132004: Sep 62005: Sep 142006: Sep 12007: Sep 252008: Aug 272009: Aug 162010: Aug 312011: Oct 62012: Sep 122013: Sep 192014: Sep 122016: Sep 102017: Sep 172018: Sep 232019: Sep 172020: Sep 92021: Sep 212022: Oct 122023: Oct 122024: Oct 182025: Oct 5

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 6Oct 5Apr 20Oct 20
2024Jun 19Oct 18Jun 17Oct 25
2023May 9Oct 12Apr 29Oct 26
2022Jun 15Oct 12May 23Oct 14
2021Jun 11Sep 21May 9Oct 12
2020Jun 9Sep 9May 7Sep 9
2019Jun 20Sep 17Jun 8Oct 2
2018May 3Sep 23Apr 18Sep 24
2017May 18Sep 17May 18Oct 1
2016May 12Sep 10May 11Oct 6
2015May 11no dataMay 11no data
2014Jun 19Sep 12May 12Sep 12
2013Jun 4Sep 19May 3Oct 5
2012Jun 13Sep 12Jun 7Oct 4
2011Jun 17Oct 6Jun 17Oct 6
2010Jun 18Aug 31May 23Sep 7
2009May 22Aug 16May 21Aug 16
2008Jun 11Aug 27May 10Sep 24
2007Jun 26Sep 25May 30Sep 30
2006May 31Sep 1May 11Sep 18
2005Jun 13Sep 14Jun 10Sep 19
2004Jun 1Sep 6May 30Sep 15
2003May 20Sep 13May 20Sep 13
2002Jun 11Sep 22May 23Sep 22
2001Jun 14Sep 8Jun 13Oct 5
2000Jun 17Sep 7May 13Sep 7
1999Jun 9Sep 8May 17Sep 27
1998Jun 5Oct 4Apr 28Oct 5
1997Jun 25Sep 27May 8Sep 27
1996May 21Aug 19May 5Sep 6
1995Jun 22Sep 21May 14Sep 21
1994Jun 7Sep 5May 2Sep 22
1993Jul 13Aug 26Jul 13Aug 27
1992May 12Aug 24May 3Aug 25
1991Jun 15Sep 15Jun 15Sep 22
1990Jun 15Oct 3May 16Oct 3
1989Jun 21Aug 25Jun 21Sep 4
1988May 20Aug 22May 11Sep 12
1987Jun 2Sep 17May 3Sep 17
1986Jul 7no dataMay 23no data
1984Jun 12Sep 22Jun 2Sep 22
1983no dataSep 10no dataSep 20
1982no dataSep 15no dataOct 8
1981Jun 15Sep 20May 13Sep 23
1980Jun 7Sep 22Apr 17Sep 22
1979Jun 8Sep 11Jun 8Oct 4
1978no dataAug 18no dataSep 19
1977May 30Sep 9May 5Oct 2
1976Jun 27Aug 27May 1Sep 8
1975May 29Aug 25May 26Sep 19
1974Jun 1Sep 2Jun 1Sep 13
1973Jun 19Sep 2May 26Oct 4
1972May 26Sep 12May 2Sep 25
1971May 21Sep 15May 18Sep 17
1970May 31Sep 9May 15Sep 15
1969Jun 30Sep 22May 3Oct 3
1968Jun 30Sep 17May 9Sep 23
1967May 26Sep 13May 14Oct 7
1966Jun 25Aug 22Jun 25Oct 1
1965May 27Aug 30May 27Aug 31
1963Jun 30Oct 10Apr 25Oct 24
1962Jun 7no dataJun 7no data
1961May 19Sep 14May 8Sep 14
1960Jun 21Aug 28Jun 21Oct 13
1959Jun 1Sep 9May 21Sep 22
1958May 13Sep 16May 1Sep 24
1957May 22Sep 11Apr 28Sep 20
1956Jun 22Sep 5May 14Sep 22
1955Jun 2Sep 22May 28Sep 22
1954Jun 29Sep 16Jun 2Sep 29
1953May 29Sep 18May 25Oct 3
1952Jun 16Sep 14May 15Sep 14
1951Jun 23Sep 12Jun 9Sep 12

"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.