Last Frost Day

Frost history / Ekalaka, MT

Ekalaka, MT: frost dates by year

Last spring and first fall frost at NOAA station USC00242689, 1951 to 2025, measured from daily minimum temperatures.

Elevation 3,432 ft, 45.886, -104.548. Download the data (JSON), NOAA daily records

Summary at 32°F

Last spring frostFirst fall frost
MedianMay 20Sep 17
EarliestApr 21 (1987)Aug 23 (2015)
LatestJun 25 (1958)Oct 24 (1963)
Trend0.7 days earlier per decade0.8 days later per decade
Years with data7371

At 28°F (hard freeze) the median last spring date is May 11 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 181954: May 271955: May 71956: May 141957: May 261958: Jun 251959: May 231960: May 291961: May 171962: May 81963: May 221964: Jun 21965: May 281966: May 231967: May 131968: May 201969: Jun 161970: May 151971: May 191972: Jun 201973: May 221974: Jun 11976: May 161977: May 201978: Jun 31979: Jun 81980: May 141981: May 91982: May 311983: Jun 41984: May 261985: May 151986: May 171987: Apr 211988: May 211990: May 171991: May 61992: May 171993: May 191994: May 41995: May 231996: May 111997: May 201998: Jun 61999: May 172000: Jun 22001: May 242002: May 242003: May 202004: Jun 182005: May 292006: May 112007: May 242008: May 102009: May 162010: May 82011: May 142012: May 252013: May 112014: May 152015: May 212016: May 152017: May 302018: May 22019: May 292020: May 112021: May 132022: May 222023: May 192024: Jun 192025: Jun 9

First fall frost (32°F)

Aug 13Aug 28Sep 12Sep 27Oct 12Oct 27Nov 1119601970198019902000201020201951: Sep 151952: Sep 211953: Sep 211954: Sep 211955: Sep 101956: Sep 41957: Sep 131958: Sep 161959: Sep 161960: Sep 171961: Sep 31962: Sep 41963: Oct 241964: Sep 101965: Aug 301966: Oct 11968: Sep 171969: Oct 51970: Sep 121971: Sep 151972: Sep 11973: Sep 141975: Sep 31976: Sep 81977: Oct 51978: Sep 211979: Sep 141980: Sep 91981: Sep 271982: Sep 151983: Sep 121984: Sep 131985: Sep 231986: Sep 71987: Sep 181990: Oct 61991: Sep 181992: Aug 251993: Sep 131994: Sep 221995: Sep 211996: Sep 221997: Sep 201998: Oct 51999: Sep 142000: Sep 222001: Oct 52002: Sep 212003: Sep 182004: Oct 12005: Oct 42006: Sep 192007: Sep 142008: Sep 52009: Sep 222010: Sep 182011: Sep 212012: Sep 122013: Oct 42014: Sep 112015: Aug 232016: Oct 52017: Sep 52018: Sep 262019: Oct 12020: Sep 82021: Sep 172022: Sep 252023: Oct 62024: Oct 12025: Sep 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 9Sep 5May 21Oct 6
2024Jun 19Oct 1May 4Oct 1
2023May 19Oct 6May 19Oct 6
2022May 22Sep 25May 22Sep 25
2021May 13Sep 17May 11Oct 14
2020May 11Sep 8May 11Sep 8
2019May 29Oct 1May 12Oct 3
2018May 2Sep 26Apr 26Oct 4
2017May 30Sep 5Apr 30Oct 4
2016May 15Oct 5May 14Oct 6
2015May 21Aug 23May 20Oct 15
2014May 15Sep 11May 15Sep 12
2013May 11Oct 4May 11Oct 5
2012May 25Sep 12May 11Oct 5
2011May 14Sep 21May 5Oct 16
2010May 8Sep 18May 8Oct 13
2009May 16Sep 22May 16Sep 28
2008May 10Sep 5May 4Oct 9
2007May 24Sep 14Apr 13Sep 14
2006May 11Sep 19May 11Oct 11
2005May 29Oct 4May 14Oct 5
2004Jun 18Oct 1May 15Oct 1
2003May 20Sep 18May 20Sep 28
2002May 24Sep 21May 24Oct 12
2001May 24Oct 5May 24Oct 5
2000Jun 2Sep 22May 18Sep 23
1999May 17Sep 14May 7Sep 28
1998Jun 6Oct 5May 7Oct 12
1997May 20Sep 20May 19Oct 9
1996May 11Sep 22May 9Sep 27
1995May 23Sep 21Apr 28Sep 21
1994May 4Sep 22Apr 30Oct 8
1993May 19Sep 13May 1Sep 14
1992May 17Aug 25Apr 25Sep 9
1991May 6Sep 18May 6Sep 18
1990May 17Oct 6May 17Oct 7
1988May 21no dataMay 4no data
1987Apr 21Sep 18Apr 21Oct 6
1986May 17Sep 7May 17Oct 11
1985May 15Sep 23May 15Sep 23
1984May 26Sep 13May 10Sep 23
1983Jun 4Sep 12May 14Sep 20
1982May 31Sep 15Apr 26Sep 19
1981May 9Sep 27Apr 12Sep 27
1980May 14Sep 9Apr 13Sep 25
1979Jun 8Sep 14May 20Oct 22
1978Jun 3Sep 21Apr 23Oct 6
1977May 20Oct 5Apr 21Oct 5
1976May 16Sep 8May 3Sep 27
1975no dataSep 3no dataSep 12
1974Jun 1no dataMay 12no data
1973May 22Sep 14May 14Sep 17
1972Jun 20Sep 1May 3Sep 21
1971May 19Sep 15May 19Sep 18
1970May 15Sep 12May 1Sep 13
1969Jun 16Oct 5May 22Oct 8
1968May 20Sep 17May 20Oct 3
1967May 13no dataMay 13no data
1966May 23Oct 1May 9Oct 10
1965May 28Aug 30May 27Sep 5
1964Jun 2Sep 10May 12Sep 12
1963May 22Oct 24May 22Oct 26
1962May 8Sep 4Apr 13Sep 4
1961May 17Sep 3May 1Sep 16
1960May 29Sep 17May 20Oct 15
1959May 23Sep 16May 14Sep 30
1958Jun 25Sep 16Jun 25Sep 27
1957May 26Sep 13Apr 17Sep 13
1956May 14Sep 4May 14Oct 6
1955May 7Sep 10Apr 28Sep 11
1954May 27Sep 21May 8Sep 21
1953May 18Sep 21May 15Sep 21
1952May 28Sep 21May 28Oct 2
1951Jun 3Sep 15Apr 25Sep 26

"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.