Last Frost Day

Frost history / Stanford, MT

Stanford, MT: frost dates by year

Last spring and first fall frost at NOAA station USC00247864, 1965 to 2025, measured from daily minimum temperatures.

Elevation 4,860 ft, 47.155, -110.224. Download the data (JSON), NOAA daily records

Summary at 32°F

Last spring frostFirst fall frost
MedianMay 24Sep 19
EarliestApr 28 (2023)Aug 22 (1966)
LatestJul 16 (1999)Oct 13 (2022)
Trend3.4 days earlier per decade3.6 days later per decade
Years with data5553

At 28°F (hard freeze) the median last spring date is May 12 and the median first fall date is Sep 30.

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 291970198019902000201020201966: Jun 131967: Jun 231968: Jun 141969: Jun 151970: May 151971: Jun 301972: May 251973: Jul 21974: Jun 71975: May 291980: May 111981: May 121982: May 311983: May 311985: May 121986: May 161987: May 221988: May 191989: May 301990: Jun 131991: May 51992: Jun 61993: Jun 41994: Jun 171995: May 271996: May 111997: May 191998: Jun 21999: Jul 162000: May 242001: May 212002: May 232003: May 192004: May 252005: May 302006: May 132007: May 152008: Jun 112009: Jun 82010: May 302011: May 192012: May 292013: May 112014: May 132015: May 202016: May 142017: May 192018: May 22019: May 192020: May 142021: May 292022: May 222023: Apr 282024: May 212025: Jun 23

First fall frost (32°F)

Aug 13Aug 28Sep 12Sep 27Oct 12Oct 271970198019902000201020201965: Aug 291966: Aug 221967: Aug 261968: Sep 211969: Sep 51970: Sep 91971: Sep 121972: Sep 71973: Sep 141974: Sep 11979: Oct 31984: Sep 131985: Sep 71986: Sep 121987: Sep 281988: Sep 111989: Sep 91990: Sep 291991: Sep 181992: Aug 221993: Sep 131994: Sep 211995: Sep 191996: Sep 231997: Sep 191998: Sep 211999: Sep 262000: Sep 202001: Oct 42002: Sep 212003: Sep 172004: Oct 12005: Sep 282006: Sep 162007: Sep 132008: Sep 22009: Sep 282010: Sep 172011: Sep 212012: Oct 32013: Sep 272014: Sep 102015: Sep 282016: Sep 132017: Sep 222018: Aug 282019: Sep 282020: Sep 72021: Sep 302022: Oct 132023: Oct 22024: Oct 12025: 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
2025Jun 23Oct 5Apr 26Oct 6
2024May 21Oct 1May 4Oct 18
2023Apr 28Oct 2Apr 23Oct 6
2022May 22Oct 13May 22Oct 23
2021May 29Sep 30May 22Oct 12
2020May 14Sep 7May 10Sep 8
2019May 19Sep 28May 9Sep 28
2018May 2Aug 28Apr 19Sep 30
2017May 19Sep 22Apr 26Oct 2
2016May 14Sep 13May 1Sep 13
2015May 20Sep 28May 18Oct 5
2014May 13Sep 10May 12Oct 3
2013May 11Sep 27May 2Oct 4
2012May 29Oct 3May 11Oct 5
2011May 19Sep 21Apr 29Oct 16
2010May 30Sep 17May 8Oct 16
2009Jun 8Sep 28Jun 8Sep 28
2008Jun 11Sep 2May 28Oct 9
2007May 15Sep 13Apr 20Sep 30
2006May 13Sep 16May 5Oct 10
2005May 30Sep 28May 14Sep 28
2004May 25Oct 1May 14Oct 1
2003May 19Sep 17May 17Sep 18
2002May 23Sep 21May 23Sep 28
2001May 21Oct 4May 7Oct 4
2000May 24Sep 20May 13Sep 21
1999Jul 16Sep 26May 8Sep 28
1998Jun 2Sep 21May 9Oct 12
1997May 19Sep 19May 19Oct 9
1996May 11Sep 23May 10Sep 24
1995May 27Sep 19May 13Sep 21
1994Jun 17Sep 21Apr 29Oct 3
1993Jun 4Sep 13Jun 3Sep 22
1992Jun 6Aug 22May 25Sep 18
1991May 5Sep 18May 5Sep 18
1990Jun 13Sep 29May 9Oct 6
1989May 30Sep 9May 25Sep 11
1988May 19Sep 11May 3Sep 19
1987May 22Sep 28May 20Oct 9
1986May 16Sep 12Apr 30Oct 3
1985May 12Sep 7May 12Sep 23
1984no dataSep 13no dataSep 23
1983May 31no dataMay 13no data
1982May 31no dataMay 12no data
1981May 12no dataApr 14no data
1980May 11no dataMay 11no data
1979no dataOct 3no dataOct 3
1975May 29no dataMay 26no data
1974Jun 7Sep 1May 17Sep 13
1973Jul 2Sep 14May 27Sep 14
1972May 25Sep 7May 2Sep 7
1971Jun 30Sep 12May 15Sep 18
1970May 15Sep 9May 13Sep 12
1969Jun 15Sep 5Jun 13Sep 15
1968Jun 14Sep 21May 19Oct 3
1967Jun 23Aug 26May 13Oct 13
1966Jun 13Aug 22May 12Sep 30
1965no dataAug 29no dataSep 5

"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.