Last Frost Day

Frost history / Broadus, MT

Broadus, MT: frost dates by year

Last spring and first fall frost at NOAA station USC00241127, 1951 to 2025, measured from daily minimum temperatures.

Elevation 3,032 ft, 45.444, -105.407. Download the data (JSON), NOAA daily records

Summary at 32°F

Last spring frostFirst fall frost
MedianMay 16Sep 19
EarliestApr 20 (2007)Aug 23 (1966)
LatestJun 25 (1958)Oct 16 (1963)
Trend1.8 days earlier per decade2.8 days later per decade
Years with data6771

At 28°F (hard freeze) the median last spring date is May 4 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 1419601970198019902000201020201951: Jun 31952: May 281953: May 151954: Jun 31955: Apr 291956: May 61957: Apr 271958: Jun 251959: May 231960: May 201961: May 71962: May 11963: May 221964: Jun 21965: Jun 81966: May 191967: May 141968: May 201969: Jun 131970: May 151971: May 201972: May 41973: May 221974: May 231975: May 261976: May 161977: Apr 281978: Apr 241979: May 231980: May 141981: May 11982: Jun 11983: Jun 61984: May 231985: May 141986: May 171987: May 41988: May 211989: Jun 11990: May 171991: May 61992: Jun 51993: May 252000: May 182001: May 72002: May 242003: May 202004: May 142005: May 142007: Apr 202008: May 42009: May 162010: May 142011: May 52013: May 112014: May 162015: May 202016: May 152017: May 202018: Apr 252019: May 122020: May 62021: May 102022: May 222023: May 12024: May 42025: May 2

First fall frost (32°F)

Aug 13Aug 28Sep 12Sep 27Oct 12Oct 2719601970198019902000201020201951: Sep 151952: Sep 221953: Sep 211954: Sep 211955: Sep 101956: Sep 61957: Oct 71958: Sep 161959: Sep 31960: Sep 91961: Sep 31962: Sep 31963: Oct 161964: Sep 121965: Sep 11966: Aug 231967: Sep 261968: Sep 221969: Sep 231970: Sep 131971: Sep 141972: Sep 171973: Sep 151974: Sep 21975: Sep 121976: Sep 91977: Sep 101978: Sep 191979: Sep 141980: Sep 41981: Sep 161982: Sep 201983: Sep 191984: Sep 131985: Sep 191986: Sep 71987: Sep 181988: Oct 51989: Sep 101990: Sep 141991: Sep 181992: Aug 251993: Sep 141995: Sep 201998: Oct 121999: Sep 152000: Sep 222001: Oct 52002: Sep 222003: Sep 302004: Oct 12005: Oct 52006: Sep 192007: Sep 142008: Sep 242009: Sep 222010: Oct 132011: Sep 212012: Oct 52013: Oct 52014: Sep 122015: Oct 152016: Oct 62017: Oct 42018: Oct 42019: Oct 12020: Sep 82021: Oct 122022: Oct 92023: 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 2no dataApr 20no data
2024May 4Sep 22May 4Oct 12
2023May 1Oct 6May 1Oct 6
2022May 22Oct 9May 22Oct 16
2021May 10Oct 12Apr 24Oct 20
2020May 6Sep 8May 6Sep 9
2019May 12Oct 1May 2Oct 3
2018Apr 25Oct 4Apr 16Oct 4
2017May 20Oct 4Apr 30Oct 4
2016May 15Oct 6May 15Oct 12
2015May 20Oct 15May 11Oct 15
2014May 16Sep 12Apr 15Oct 3
2013May 11Oct 5May 3Oct 5
2012no dataOct 5no dataOct 5
2011May 5Sep 21May 5Oct 19
2010May 14Oct 13May 8Oct 13
2009May 16Sep 22May 14Oct 3
2008May 4Sep 24May 3Oct 9
2007Apr 20Sep 14Apr 14Sep 14
2006no dataSep 19no dataOct 11
2005May 14Oct 5May 3Oct 6
2004May 14Oct 1May 14Oct 25
2003May 20Sep 30May 20Sep 30
2002May 24Sep 22May 24Oct 13
2001May 7Oct 5May 4Oct 5
2000May 18Sep 22May 15Sep 24
1999no dataSep 15no dataOct 16
1998no dataOct 12no dataOct 12
1995no dataSep 20no dataSep 21
1993May 25Sep 14May 1Sep 14
1992Jun 5Aug 25Apr 26Aug 25
1991May 6Sep 18May 5Sep 18
1990May 17Sep 14May 12Oct 7
1989Jun 1Sep 10May 1Sep 10
1988May 21Oct 5May 4Oct 23
1987May 4Sep 18Apr 21Oct 6
1986May 17Sep 7May 16Oct 11
1985May 14Sep 19May 14Sep 23
1984May 23Sep 13May 8Sep 23
1983Jun 6Sep 19May 17Sep 20
1982Jun 1Sep 20May 30Oct 7
1981May 1Sep 16Apr 14Sep 27
1980May 14Sep 4May 14Sep 25
1979May 23Sep 14May 11Sep 14
1978Apr 24Sep 19Apr 24Sep 20
1977Apr 28Sep 10Apr 25Sep 19
1976May 16Sep 9May 7Sep 27
1975May 26Sep 12May 1Sep 12
1974May 23Sep 2May 23Sep 13
1973May 22Sep 15May 22Oct 3
1972May 4Sep 17Apr 24Sep 21
1971May 20Sep 14May 19Sep 18
1970May 15Sep 13May 1Sep 15
1969Jun 13Sep 23May 22Oct 5
1968May 20Sep 22May 20Oct 2
1967May 14Sep 26May 14Sep 27
1966May 19Aug 23May 2Oct 10
1965Jun 8Sep 1May 27Sep 16
1964Jun 2Sep 12Apr 17Sep 27
1963May 22Oct 16May 22Oct 26
1962May 1Sep 3Apr 13Sep 4
1961May 7Sep 3Apr 28Sep 14
1960May 20Sep 9Apr 30Sep 30
1959May 23Sep 3May 7Sep 30
1958Jun 25Sep 16Apr 29Sep 27
1957Apr 27Oct 7Apr 17Oct 8
1956May 6Sep 6Apr 30Sep 6
1955Apr 29Sep 10Apr 28Sep 11
1954Jun 3Sep 21May 8Sep 21
1953May 15Sep 21May 12Sep 21
1952May 28Sep 22Apr 22Oct 2
1951Jun 3Sep 15May 7Sep 27

"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.