Last Frost Day

Frost history / Turner 11N, MT

Turner 11N, MT: frost dates by year

Last spring and first fall frost at NOAA station USC00248415, 1986 to 2025, measured from daily minimum temperatures.

Elevation 2,982 ft, 48.999, -108.389. Download the data (JSON), NOAA daily records

Summary at 32°F

Last spring frostFirst fall frost
MedianMay 17Sep 21
EarliestMay 1 (2018)Aug 31 (1994)
LatestJun 10 (2009)Oct 7 (2008)
Trendlittle change (less than half a day per decade)1.0 days later per decade
Years with data3737

At 28°F (hard freeze) the median last spring date is May 7 and the median first fall date is Sep 29.

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 2919902000201020201986: May 161987: May 201988: May 31989: May 51990: May 171991: May 51992: May 251993: May 181994: May 41995: May 271996: May 111997: May 151998: Jun 41999: May 122000: Jun 42001: May 212002: May 232003: May 202004: May 242005: May 142006: May 112007: May 242008: May 102009: Jun 102010: May 302011: May 112012: May 292013: May 112014: May 172015: May 292016: May 152017: May 182018: May 12019: May 182020: May 142024: May 32025: May 6

First fall frost (32°F)

Aug 13Aug 28Sep 12Sep 27Oct 1219902000201020201986: Sep 301987: Oct 51988: Sep 191989: Sep 101990: Sep 221991: Sep 171993: Sep 131994: Aug 311995: Sep 191996: Sep 221997: Sep 191998: Oct 51999: Sep 92000: Sep 112001: Oct 42002: Sep 222003: Sep 182004: Sep 212005: Sep 242006: Sep 172007: Sep 132008: Oct 72009: Sep 282010: Sep 172011: Sep 142012: Sep 122013: Sep 272014: Sep 112015: Sep 222016: Sep 132017: Sep 212018: Sep 282019: Sep 272020: Sep 82022: Sep 212024: Oct 32025: Oct 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
2025May 6Oct 5Apr 24Oct 5
2024May 3Oct 3May 3Oct 13
2022no dataSep 21no dataSep 21
2020May 14Sep 8May 12Sep 8
2019May 18Sep 27May 7Sep 28
2018May 1Sep 28Apr 14Sep 28
2017May 18Sep 21Apr 29Oct 4
2016May 15Sep 13May 14Oct 6
2015May 29Sep 22May 19Sep 29
2014May 17Sep 11May 14Oct 3
2013May 11Sep 27May 11Oct 4
2012May 29Sep 12May 11Oct 6
2011May 11Sep 14Apr 22Oct 14
2010May 30Sep 17May 12Sep 18
2009Jun 10Sep 28May 21Sep 28
2008May 10Oct 7May 10Oct 9
2007May 24Sep 13May 5Sep 14
2006May 11Sep 17Apr 25Oct 8
2005May 14Sep 24May 14Sep 24
2004May 24Sep 21May 14Oct 1
2003May 20Sep 18May 11Sep 18
2002May 23Sep 22May 23Sep 23
2001May 21Oct 4May 21Oct 4
2000Jun 4Sep 11May 7Sep 22
1999May 12Sep 9Apr 24Sep 14
1998Jun 4Oct 5May 7Oct 5
1997May 15Sep 19May 2Sep 19
1996May 11Sep 22May 10Oct 2
1995May 27Sep 19May 24Sep 19
1994May 4Aug 31May 4Oct 23
1993May 18Sep 13Apr 27Sep 22
1992May 25no dataMay 22no data
1991May 5Sep 17May 5Sep 18
1990May 17Sep 22May 11Sep 22
1989May 5Sep 10May 5Sep 11
1988May 3Sep 19Apr 27Oct 3
1987May 20Oct 5Apr 20Oct 9
1986May 16Sep 30May 1Oct 11

"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.