Last Frost Day

Frost history / Medicine Lake 3 Se, MT

Medicine Lake 3 Se, MT: frost dates by year

Last spring and first fall frost at NOAA station USC00245572, 1951 to 2025, measured from daily minimum temperatures.

Elevation 1,942 ft, 48.483, -104.451. Download the data (JSON), NOAA daily records

Summary at 32°F

Last spring frostFirst fall frost
MedianMay 16Sep 19
EarliestApr 13 (1987)Aug 11 (1964)
LatestJun 20 (1969)Oct 26 (1963)
Trend0.6 days earlier per decade0.9 days later per decade
Years with data6261

At 28°F (hard freeze) the median last spring date is May 8 and the median first fall date is Sep 24.

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 2919601970198019902000201020201951: Jun 31952: May 311953: May 151954: May 311955: Apr 291956: May 71957: May 251958: May 151959: May 201960: Jun 51961: May 91962: May 81963: May 221964: Jun 11965: May 271966: May 121967: May 121968: May 201969: Jun 201970: May 151971: May 201972: May 91973: May 161974: May 171975: May 311976: May 71977: May 61978: Apr 211979: May 201980: May 131981: May 111982: May 81983: May 151984: May 111985: Jun 41986: May 171987: Apr 131988: May 91989: May 61990: May 171991: May 61992: May 251993: May 191994: May 91995: May 171996: May 131997: May 291998: Jun 41999: May 112000: Jun 22001: May 242003: May 212005: May 152009: Jun 52013: May 102014: May 142017: May 182019: May 272021: May 132022: Jun 32024: Apr 232025: May 6

First fall frost (32°F)

Jul 29Aug 13Aug 28Sep 12Sep 27Oct 12Oct 27Nov 1119601970198019902000201020201951: Sep 231952: Sep 201953: Sep 211954: Sep 211955: Sep 101956: Sep 41957: Sep 181958: Sep 271959: Sep 151960: Sep 171961: Sep 241962: Sep 31963: Oct 261964: Aug 111965: Sep 41966: Sep 141967: Sep 271968: Oct 11969: Sep 161970: Sep 121971: Sep 181972: Sep 211973: Sep 161974: Sep 21975: Sep 121976: Sep 101977: Oct 31978: Oct 61979: Oct 41980: Sep 221981: Sep 161982: Sep 151983: Sep 191984: Sep 231985: Sep 231986: Oct 111987: Oct 21988: Sep 191989: Sep 101990: Sep 291991: Sep 191992: Sep 181994: Sep 221995: Sep 191996: Sep 261997: Sep 191999: Sep 142000: Sep 222001: Oct 32003: Sep 152005: Sep 222009: Oct 62012: Sep 62013: Sep 192018: Sep 52019: Sep 302020: Sep 72021: Sep 242022: Oct 62023: Oct 62024: Sep 22

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 6no dataMay 2no data
2024Apr 23Sep 22Apr 22Oct 3
2023no dataOct 6no dataOct 6
2022Jun 3Oct 6May 10Oct 7
2021May 13Sep 24May 10Oct 15
2020no dataSep 7no dataSep 7
2019May 27Sep 30May 11Sep 30
2018no dataSep 5no dataSep 28
2017May 18no dataApr 27no data
2014May 14no dataMay 13no data
2013May 10Sep 19May 10Oct 4
2012no dataSep 6no dataSep 13
2009Jun 5Oct 6May 16Oct 8
2005May 15Sep 22May 15Sep 28
2003May 21Sep 15May 12Sep 20
2001May 24Oct 3Apr 23Oct 4
2000Jun 2Sep 22May 13Oct 5
1999May 11Sep 14May 7Sep 28
1998Jun 4no dataMay 2no data
1997May 29Sep 19May 20Sep 20
1996May 13Sep 26May 12Sep 26
1995May 17Sep 19Apr 27Sep 21
1994May 9Sep 22May 1Oct 9
1993May 19no dataApr 30no data
1992May 25Sep 18Apr 25Sep 18
1991May 6Sep 19May 6Sep 19
1990May 17Sep 29May 3Sep 29
1989May 6Sep 10May 5Sep 12
1988May 9Sep 19May 9Oct 3
1987Apr 13Oct 2Apr 13Oct 7
1986May 17Oct 11May 1Oct 12
1985Jun 4Sep 23Apr 13Sep 24
1984May 11Sep 23May 8Sep 23
1983May 15Sep 19May 13Sep 20
1982May 8Sep 15May 8Sep 15
1981May 11Sep 16May 9Oct 6
1980May 13Sep 22May 11Oct 11
1979May 20Oct 4May 11Oct 9
1978Apr 21Oct 6Apr 20Oct 6
1977May 6Oct 3May 1Oct 4
1976May 7Sep 10May 6Sep 23
1975May 31Sep 12May 2Oct 10
1974May 17Sep 2May 4Sep 13
1973May 16Sep 16May 14Sep 16
1972May 9Sep 21May 6Sep 21
1971May 20Sep 18May 19Sep 18
1970May 15Sep 12May 1Sep 13
1969Jun 20Sep 16Jun 12Oct 8
1968May 20Oct 1May 20Oct 3
1967May 12Sep 27May 12Oct 18
1966May 12Sep 14May 2Sep 14
1965May 27Sep 4May 27Sep 5
1964Jun 1Aug 11May 31Sep 11
1963May 22Oct 26May 3Oct 27
1962May 8Sep 3May 8Sep 3
1961May 9Sep 24Apr 30Sep 30
1960Jun 5Sep 17May 7Sep 17
1959May 20Sep 15May 14Sep 16
1958May 15Sep 27May 1Sep 30
1957May 25Sep 18Apr 17Sep 19
1956May 7Sep 4May 4Sep 5
1955Apr 29Sep 10Apr 12Sep 10
1954May 31Sep 21May 31Sep 21
1953May 15Sep 21May 13Sep 21
1952May 31Sep 20May 28Sep 22
1951Jun 3Sep 23Jun 1Sep 23

"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.