Last Frost Day

Frost history / Havre City Co Ap, MT

Havre City Co Ap, MT: frost dates by year

Last spring and first fall frost at NOAA station USW00094012, 1961 to 2024, measured from daily minimum temperatures.

Elevation 2,585 ft, 48.543, -109.763. Download the data (JSON), NOAA daily records

Summary at 32°F

Last spring frostFirst fall frost
MedianMay 15Sep 21
EarliestApr 14 (1978)Sep 2 (1974)
LatestJun 11 (1985)Oct 15 (1967)
Trend0.6 days later per decade1.1 days later per decade
Years with data6364

At 28°F (hard freeze) the median last spring date is May 5 and the median first fall date is Oct 2.

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 291970198019902000201020201962: May 51963: May 211964: May 261965: May 211966: May 191967: May 131968: May 191969: Jun 11970: May 121971: May 181972: May 51973: May 121974: Apr 281975: May 21976: May 181977: May 61978: Apr 141979: Jun 11980: May 111981: May 31982: May 311983: May 131984: May 111985: Jun 111986: May 161987: Apr 201988: May 31989: May 11990: May 161991: May 51992: Jun 61993: Apr 251994: Apr 301995: May 231996: May 111997: May 191998: Jun 21999: May 112000: May 242001: May 72002: May 232003: May 202004: May 232005: May 282006: May 52007: May 52008: May 102009: Jun 102010: May 212011: May 112012: May 272013: May 62014: May 132015: May 192016: May 292017: May 152018: Apr 262019: May 202020: May 142021: May 222022: Jun 22023: Apr 282024: May 20

First fall frost (32°F)

Aug 28Sep 12Sep 27Oct 12Oct 271970198019902000201020201961: Sep 131962: Sep 31963: Oct 81964: Sep 121965: Sep 151966: Sep 301967: Oct 151968: Oct 21969: Oct 71970: Sep 111971: Sep 181972: Sep 201973: Sep 161974: Sep 21975: Sep 201976: Sep 191977: Sep 221978: Sep 201979: Oct 31980: Sep 161981: Sep 231982: Sep 131983: Sep 61984: Sep 141985: Sep 201986: Oct 31987: Oct 51988: Sep 81989: Sep 101990: Sep 221991: Sep 171992: Sep 61993: Sep 131994: Oct 51995: Sep 201996: Sep 221997: Sep 181998: Sep 221999: Sep 192000: Sep 212001: Sep 162002: Sep 222003: Sep 142004: Sep 302005: Sep 212006: Sep 272007: Sep 132008: Sep 242009: Sep 272010: Oct 142011: Sep 292012: Oct 12013: Oct 32014: Sep 122015: Sep 282016: Sep 132017: Sep 252018: Sep 282019: Sep 282020: Oct 12021: Sep 172022: Sep 212023: Oct 52024: Oct 3

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
2024May 20Oct 3May 4Oct 23
2023Apr 28Oct 5Apr 23Oct 6
2022Jun 2Sep 21May 22Oct 7
2021May 22Sep 17Apr 24Oct 2
2020May 14Oct 1Apr 19Oct 15
2019May 20Sep 28May 9Sep 30
2018Apr 26Sep 28Apr 24Oct 8
2017May 15Sep 25Apr 18Oct 3
2016May 29Sep 13May 14Oct 6
2015May 19Sep 28May 18Oct 15
2014May 13Sep 12May 13Oct 3
2013May 6Oct 3May 2Oct 4
2012May 27Oct 1May 12Oct 5
2011May 11Sep 29Apr 30Sep 29
2010May 21Oct 14May 12Oct 14
2009Jun 10Sep 27May 21Sep 27
2008May 10Sep 24May 10Oct 8
2007May 5Sep 13Apr 21Sep 14
2006May 5Sep 27May 5Oct 8
2005May 28Sep 21May 27Sep 28
2004May 23Sep 30May 14Oct 1
2003May 20Sep 14May 7Sep 18
2002May 23Sep 22May 10Sep 22
2001May 7Sep 16May 3Oct 4
2000May 24Sep 21May 7Sep 22
1999May 11Sep 19May 6Oct 2
1998Jun 2Sep 22May 2Oct 5
1997May 19Sep 18May 11Sep 18
1996May 11Sep 22May 6Sep 24
1995May 23Sep 20May 13Sep 20
1994Apr 30Oct 5Apr 29Oct 8
1993Apr 25Sep 13Apr 25Sep 13
1992Jun 6Sep 6Apr 25Sep 6
1991May 5Sep 17May 5Sep 17
1990May 16Sep 22Apr 30Oct 6
1989May 1Sep 10Apr 30Sep 11
1988May 3Sep 8May 3Oct 5
1987Apr 20Oct 5Apr 20Oct 5
1986May 16Oct 3May 16Oct 10
1985Jun 11Sep 20May 6Sep 28
1984May 11Sep 14May 5Sep 23
1983May 13Sep 6May 11Sep 18
1982May 31Sep 13May 31Sep 15
1981May 3Sep 23Apr 26Oct 5
1980May 11Sep 16Apr 8Sep 25
1979Jun 1Oct 3May 10Oct 9
1978Apr 14Sep 20Apr 13Oct 3
1977May 6Sep 22May 6Oct 4
1976May 18Sep 19May 3Sep 27
1975May 2Sep 20Apr 21Oct 9
1974Apr 28Sep 2Apr 15Sep 27
1973May 12Sep 16Apr 22Sep 17
1972May 5Sep 20May 2Sep 26
1971May 18Sep 18May 18Sep 18
1970May 12Sep 11Apr 30Sep 12
1969Jun 1Oct 7May 21Oct 7
1968May 19Oct 2May 11Oct 2
1967May 13Oct 15May 5Oct 17
1966May 19Sep 30May 19Oct 10
1965May 21Sep 15May 18Sep 18
1964May 26Sep 12Apr 19Oct 4
1963May 21Oct 8May 19Oct 27
1962May 5Sep 3Apr 13Sep 9
1961no dataSep 13no dataSep 19

"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.