Last Frost Day

Frost history / Cottonwood 2 Wsw, ID

Cottonwood 2 Wsw, ID: frost dates by year

Last spring and first fall frost at NOAA station USC00102159, 1977 to 2025, measured from daily minimum temperatures.

Elevation 3,945 ft, 46.034, -116.392. Download the data (JSON) · NOAA daily records

Summary at 32°F

Last spring frostFirst fall frost
MedianMay 12Oct 8
EarliestApr 5 (2016)Aug 24 (1992)
LatestJun 8 (1999)Nov 4 (2015)
Trend2.3 days earlier per decade3.8 days later per decade
Years with data4141

At 28°F (hard freeze) the median last spring date is Apr 25 and the median first fall date is Oct 23.

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 14198019902000201020201977: May 161978: May 51980: May 231981: May 71982: May 51983: May 121984: May 311985: May 121986: May 231987: Apr 191988: May 291989: May 291990: May 91991: May 91992: May 121993: May 71994: May 211995: Jun 71996: May 91997: May 21998: May 261999: Jun 82000: May 312001: May 32002: May 92003: May 192004: Apr 292005: Apr 292006: May 92007: May 52008: May 122010: May 212013: May 232016: Apr 52018: Apr 222019: May 12020: May 72022: May 132023: Apr 242024: May 202025: May 19

First fall frost (32°F)

Aug 13Aug 28Sep 12Sep 27Oct 12Oct 27Nov 11198019902000201020201978: Oct 131980: Oct 221981: Sep 261982: Oct 51983: Sep 191984: Sep 231985: Sep 281986: Oct 111987: Oct 151988: Oct 271989: Oct 31990: Oct 61991: Oct 181992: Aug 241993: Sep 221994: Oct 41995: Oct 51996: Sep 231997: Oct 81998: Oct 111999: Sep 272000: Sep 222001: Oct 82002: Oct 12003: Oct 252004: Oct 242005: Oct 52006: Oct 102007: Sep 292008: Oct 92009: Oct 82015: Nov 42016: Oct 112017: Oct 42018: Oct 142019: Sep 292020: Oct 222022: Oct 232023: Oct 262024: Oct 182025: Oct 27

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 19Oct 27Apr 4Nov 25
2024May 20Oct 18May 1Nov 6
2023Apr 24Oct 26Apr 19Oct 27
2022May 13Oct 23Apr 20Nov 3
2020May 7Oct 22Apr 16Oct 22
2019May 1Sep 29Apr 30Oct 10
2018Apr 22Oct 14Apr 18Oct 14
2017no dataOct 4no dataOct 14
2016Apr 5Oct 11Mar 28Nov 17
2015no dataNov 4no dataNov 5
2013May 23no dataMay 1no data
2010May 21no dataMay 7no data
2009no dataOct 8no dataOct 10
2008May 12Oct 9Apr 22Oct 11
2007May 5Sep 29Apr 20Oct 27
2006May 9Oct 10May 2Oct 30
2005Apr 29Oct 5Apr 28Nov 8
2004Apr 29Oct 24Apr 1Oct 25
2003May 19Oct 25May 19Oct 29
2002May 9Oct 1May 8Oct 12
2001May 3Oct 8Apr 15Nov 7
2000May 31Sep 22Apr 5Sep 23
1999Jun 8Sep 27May 10Oct 16
1998May 26Oct 11Apr 25Oct 17
1997May 2Oct 8May 2Oct 8
1996May 9Sep 23May 4Oct 17
1995Jun 7Oct 5Apr 15Oct 30
1994May 21Oct 4Apr 14Oct 30
1993May 7Sep 22May 7Nov 5
1992May 12Aug 24Apr 23Oct 15
1991May 9Oct 18Apr 26Oct 28
1990May 9Oct 6Mar 25Oct 20
1989May 29Oct 3Apr 4Oct 28
1988May 29Oct 27May 2Oct 27
1987Apr 19Oct 15Apr 19Nov 14
1986May 23Oct 11Apr 30Nov 7
1985May 12Sep 28Apr 26Sep 28
1984May 31Sep 23Apr 29Oct 15
1983May 12Sep 19Apr 13Sep 20
1982May 5Oct 5May 4Oct 18
1981May 7Sep 26Apr 13Sep 26
1980May 23Oct 22Apr 7Oct 23
1978May 5Oct 13May 5Oct 23
1977May 16no dataMay 5no data

"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.