Last Frost Day

Frost history / Melstone, MT

Melstone, MT: frost dates by year

Last spring and first fall frost at NOAA station USC00245596, 1951 to 2025, measured from daily minimum temperatures.

Elevation 2,932 ft, 46.601, -107.871. Download the data (JSON), NOAA daily records

Summary at 32°F

Last spring frostFirst fall frost
MedianMay 12Sep 26
EarliestApr 18 (2025)Aug 25 (1992)
LatestJun 14 (1969)Oct 23 (2023)
Trend1.2 days earlier per decade1.9 days later per decade
Years with data7264

At 28°F (hard freeze) the median last spring date is Apr 30 and the median first fall date is Oct 6.

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: May 41952: May 171953: May 211954: May 311955: May 111956: May 31957: May 241958: May 131959: May 201960: May 241961: May 81962: Apr 301963: May 231964: Apr 271965: May 271966: May 171967: May 121968: May 201969: Jun 141970: May 131972: May 111973: May 211974: May 231975: May 31976: May 31977: Apr 281978: Apr 241979: Jun 81980: May 121981: May 91982: May 311983: May 151984: May 81985: May 141986: May 171987: May 201988: May 31989: May 21990: May 141991: May 51992: May 251993: Apr 211994: May 41995: May 221996: May 111997: May 191998: May 101999: May 72000: May 142001: May 72002: May 232003: May 202005: May 132006: May 112007: Apr 222008: May 32009: May 212010: May 82011: May 52012: May 292013: May 52014: May 122015: May 162016: May 142017: May 192018: Apr 242019: May 92021: May 222022: May 222023: Apr 232024: May 42025: Apr 18

First fall frost (32°F)

Aug 13Aug 28Sep 12Sep 27Oct 12Oct 27Nov 1119601970198019902000201020201951: Sep 151952: Oct 51953: Sep 211954: Sep 211955: Sep 101956: Sep 51957: Oct 51958: Sep 271959: Sep 291960: Sep 81961: Sep 31963: Oct 81964: Sep 111967: Oct 71968: Sep 221969: Oct 71970: Sep 121971: Sep 181973: Oct 31974: Sep 131975: Sep 201976: Sep 271978: Oct 31979: Oct 91980: Sep 251981: Sep 271982: Sep 201983: Sep 191984: Sep 231986: Oct 111987: Oct 51988: Sep 191989: Sep 111991: Sep 181992: Aug 251993: Sep 221994: Oct 31995: Sep 211996: Sep 231997: Oct 61998: Oct 121999: Sep 302000: Sep 222001: Oct 52002: Sep 222003: Sep 182004: Sep 212005: Oct 42007: Sep 142008: Oct 92009: Sep 282010: Oct 122012: Sep 122013: Oct 92014: Sep 122015: Oct 152016: Oct 52017: Oct 92018: Sep 302019: Sep 292021: Sep 172022: Oct 152023: Oct 232024: Oct 13

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
2025Apr 18no dataMar 19no data
2024May 4Oct 13Apr 20Oct 23
2023Apr 23Oct 23Apr 22Oct 23
2022May 22Oct 15May 22Oct 24
2021May 22Sep 17Apr 23Oct 20
2019May 9Sep 29May 9Sep 29
2018Apr 24Sep 30Apr 14Oct 12
2017May 19Oct 9Apr 5Oct 9
2016May 14Oct 5Apr 17Oct 10
2015May 16Oct 15Apr 20Oct 16
2014May 12Sep 12Apr 15Oct 3
2013May 5Oct 9May 2Oct 16
2012May 29Sep 12May 26Oct 6
2011May 5no dataApr 24no data
2010May 8Oct 12May 8Oct 16
2009May 21Sep 28May 2Sep 28
2008May 3Oct 9Apr 27Oct 9
2007Apr 22Sep 14Apr 13Oct 27
2006May 11no dataMay 5no data
2005May 13Oct 4May 3Oct 6
2004no dataSep 21no dataOct 1
2003May 20Sep 18Apr 7Sep 18
2002May 23Sep 22May 9Oct 12
2001May 7Oct 5Apr 17Oct 5
2000May 14Sep 22Apr 16Sep 22
1999May 7Sep 30Apr 17Oct 3
1998May 10Oct 12May 7Oct 12
1997May 19Oct 6May 19Oct 9
1996May 11Sep 23May 9Sep 27
1995May 22Sep 21May 1Sep 21
1994May 4Oct 3Apr 29Oct 23
1993Apr 21Sep 22Apr 15Sep 22
1992May 25Aug 25Apr 12Sep 18
1991May 5Sep 18May 5Sep 18
1990May 14no dataMay 1no data
1989May 2Sep 11Apr 17Sep 11
1988May 3Sep 19Apr 26Oct 23
1987May 20Oct 5Apr 20Oct 10
1986May 17Oct 11May 16Oct 11
1985May 14no dataApr 26no data
1984May 8Sep 23May 8Sep 23
1983May 15Sep 19May 15Sep 20
1982May 31Sep 20Apr 30Oct 6
1981May 9Sep 27Apr 14Oct 13
1980May 12Sep 25May 12Oct 17
1979Jun 8Oct 9May 8Oct 9
1978Apr 24Oct 3Apr 23Oct 6
1977Apr 28no dataApr 21no data
1976May 3Sep 27May 2Oct 5
1975May 3Sep 20Apr 27Sep 20
1974May 23Sep 13Apr 29Oct 5
1973May 21Oct 3May 12Oct 8
1972May 11no dataMay 2no data
1971no dataSep 18no dataOct 22
1970May 13Sep 12Apr 30Sep 14
1969Jun 14Oct 7Jun 14Oct 11
1968May 20Sep 22May 19Oct 3
1967May 12Oct 7May 12Oct 20
1966May 17no dataMay 12no data
1965May 27no dataApr 27no data
1964Apr 27Sep 11Apr 18Sep 27
1963May 23Oct 8May 22Oct 21
1962Apr 30no dataApr 29no data
1961May 8Sep 3May 8Sep 22
1960May 24Sep 8Apr 30Oct 15
1959May 20Sep 29May 12Sep 29
1958May 13Sep 27Apr 28Sep 30
1957May 24Oct 5Apr 21Oct 5
1956May 3Sep 5Apr 28Oct 6
1955May 11Sep 10Apr 28Sep 22
1954May 31Sep 21May 6Sep 30
1953May 21Sep 21May 13Oct 3
1952May 17Oct 5May 17Oct 5
1951May 4Sep 15Apr 25Sep 15

"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.