Last Frost Day

Frost history / Missoula 2 Ne, MT

Missoula 2 Ne, MT: frost dates by year

Last spring and first fall frost at NOAA station USC00245735, 1967 to 2013, measured from daily minimum temperatures.

Elevation 3,420 ft, 46.898, -113.968. Download the data (JSON) · NOAA daily records

Summary at 32°F

Last spring frostFirst fall frost
MedianMay 20Sep 21
EarliestApr 26 (1998)Aug 25 (1992)
LatestJul 7 (1971)Oct 11 (2010)
Trend3.0 days earlier per decade4.7 days later per decade
Years with data4745

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

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 14197019801990200020101967: May 261968: May 61969: May 211970: May 141971: Jul 71972: May 261973: May 271974: May 311975: May 261976: Jun 41977: May 301978: May 261979: May 301980: May 111981: May 91982: May 301983: May 131984: Jun 11985: May 131986: May 231987: Jun 21988: May 181989: May 201990: Jun 51991: May 261992: May 161993: Apr 281994: May 11995: Jun 71996: May 91997: May 81998: Apr 261999: May 152000: May 132001: Jun 42002: May 152003: May 182004: May 142005: May 252006: May 132007: May 62008: May 132009: May 212010: May 212011: May 172012: May 122013: May 25

First fall frost (32°F)

Aug 13Aug 28Sep 12Sep 27Oct 12Oct 27197019801990200020101967: Sep 131968: Oct 21969: Sep 151970: Sep 101971: Sep 141972: Sep 101973: Sep 161974: Sep 131975: Sep 201976: Sep 81977: Oct 21978: Sep 171979: Oct 91980: Aug 291981: Sep 221982: Sep 151983: Sep 101984: Sep 131985: Sep 201986: Sep 221987: Sep 171988: Sep 211989: Oct 51990: Oct 61991: Sep 221992: Aug 251993: Sep 131994: Oct 71995: Sep 211997: Oct 81998: Oct 41999: Sep 272000: Sep 212001: Oct 52002: Sep 212003: Oct 92004: Oct 92005: Oct 92006: Oct 82007: Sep 252008: Oct 82009: Oct 32010: Oct 112011: Oct 92012: Sep 12

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
2013May 25no dataMay 2no data
2012May 12Sep 12May 11Oct 5
2011May 17Oct 9Apr 29Oct 18
2010May 21Oct 11May 7Oct 12
2009May 21Oct 3May 9Oct 5
2008May 13Oct 8May 13Oct 9
2007May 6Sep 25May 4Oct 26
2006May 13Oct 8May 10Oct 10
2005May 25Oct 9Apr 29Oct 9
2004May 14Oct 9May 13Oct 11
2003May 18Oct 9May 18Oct 10
2002May 15Sep 21May 9Sep 22
2001Jun 4Oct 5Apr 22Oct 5
2000May 13Sep 21Apr 8Sep 22
1999May 15Sep 27May 13Sep 28
1998Apr 26Oct 4Apr 18Oct 5
1997May 8Oct 8Apr 13Oct 8
1996May 9no dataMay 6no data
1995Jun 7Sep 21Apr 21Sep 22
1994May 1Oct 7Apr 29Oct 29
1993Apr 28Sep 13Apr 28Sep 21
1992May 16Aug 25May 12Sep 7
1991May 26Sep 22Apr 25Oct 8
1990Jun 5Oct 6May 8Oct 6
1989May 20Oct 5May 20Oct 17
1988May 18Sep 21Apr 25Oct 27
1987Jun 2Sep 17Apr 20Sep 17
1986May 23Sep 22May 23Oct 3
1985May 13Sep 20May 13Sep 28
1984Jun 1Sep 13May 7Sep 25
1983May 13Sep 10May 12Sep 20
1982May 30Sep 15May 5Oct 9
1981May 9Sep 22May 5Oct 5
1980May 11Aug 29Apr 16Oct 19
1979May 30Oct 9Apr 21Oct 30
1978May 26Sep 17May 5Sep 17
1977May 30Oct 2May 6Oct 4
1976Jun 4Sep 8Apr 21Oct 4
1975May 26Sep 20May 1Oct 16
1974May 31Sep 13May 19Sep 13
1973May 27Sep 16May 27Oct 2
1972May 26Sep 10May 1Sep 27
1971Jul 7Sep 14May 21Sep 18
1970May 14Sep 10Apr 29Sep 14
1969May 21Sep 15Apr 27Sep 15
1968May 6Oct 2Apr 23Oct 3
1967May 26Sep 13May 25Oct 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 1991–2020 frost probabilities.