Last Frost Day

Frost history / Kaycee, WY

Kaycee, WY: frost dates by year

Last spring and first fall frost at NOAA station USC00485055, 1951 to 2025, measured from daily minimum temperatures.

Elevation 4,660 ft, 43.714, -106.638. Download the data (JSON), NOAA daily records

Summary at 32°F

Last spring frostFirst fall frost
MedianMay 22Sep 18
EarliestMay 1 (1992)Aug 20 (1964)
LatestJul 5 (2018)Oct 16 (2015)
Trend2.3 days earlier per decade2.9 days later per decade
Years with data7273

At 28°F (hard freeze) the median last spring date is May 8 and the median first fall date is Oct 3.

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 91952: May 311953: Jun 251954: Jun 81955: May 291956: May 141957: May 231958: May 51959: Jun 11960: Jun 211961: May 81962: May 231963: May 221964: Jun 21965: May 271966: May 241967: May 171968: May 211969: Jun 141970: Jun 131971: May 201972: Jul 41973: Jun 41974: May 311975: May 291976: Jun 141977: May 291978: May 131979: May 311980: May 141981: May 141982: Jun 71983: Jun 11984: May 231985: May 131986: May 251987: May 41988: May 91990: May 131991: May 31992: May 11993: May 91994: May 61995: May 241996: May 201998: Jun 41999: May 162000: May 132001: May 202002: May 232003: May 192004: May 152005: May 122006: May 112008: May 42009: May 262010: May 142011: May 172012: May 132013: May 72014: May 142015: May 212016: May 182017: May 222018: Jul 52019: May 242020: May 252021: May 132022: May 232023: May 22024: May 232025: May 3

First fall frost (32°F)

Aug 13Aug 28Sep 12Sep 27Oct 12Oct 2719601970198019902000201020201951: Sep 151952: Aug 311953: Sep 211954: Sep 191955: Sep 211956: Aug 311957: Sep 91958: Sep 151959: Sep 21960: Sep 91961: Sep 31962: Aug 281963: Oct 111964: Aug 201965: Aug 311966: Aug 221967: Sep 271968: Sep 171969: Sep 151970: Sep 101971: Sep 151972: Sep 211973: Sep 151974: Sep 31975: Sep 121976: Sep 91977: Sep 91978: Sep 141979: Sep 141980: Sep 221981: Sep 261982: Sep 121983: Sep 191984: Sep 231985: Sep 201987: Sep 181988: Sep 191989: Sep 111990: Oct 61991: Sep 171992: Sep 71993: Sep 131994: Sep 211995: Sep 191996: Sep 181997: Oct 81998: Oct 51999: Sep 112000: Sep 212001: Oct 42002: Sep 212003: Sep 172004: Sep 212005: Sep 252006: Sep 232007: Sep 92008: Aug 222010: Sep 82011: Sep 212012: Oct 42013: Sep 272014: Sep 112015: Oct 162016: Oct 122017: Sep 262018: Sep 262019: Oct 22020: Sep 82021: Sep 222022: Oct 92023: Oct 72024: Oct 62025: Oct 7

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 3Oct 7Apr 23Oct 13
2024May 23Oct 6May 5Oct 23
2023May 2Oct 7Apr 29Oct 26
2022May 23Oct 9Apr 26Oct 13
2021May 13Sep 22May 10Oct 12
2020May 25Sep 8May 10Sep 9
2019May 24Oct 2May 11Oct 3
2018Jul 5Sep 26Apr 26Oct 12
2017May 22Sep 26May 1Oct 4
2016May 18Oct 12Apr 9Oct 12
2015May 21Oct 16May 12Oct 16
2014May 14Sep 11May 14Sep 14
2013May 7Sep 27May 2Oct 5
2012May 13Oct 4May 1Oct 6
2011May 17Sep 21May 14Oct 19
2010May 14Sep 8May 11Oct 27
2009May 26no dataMay 26no data
2008May 4Aug 22May 4Oct 10
2007no dataSep 9no dataOct 14
2006May 11Sep 23May 5Oct 11
2005May 12Sep 25May 12Oct 4
2004May 15Sep 21May 15Oct 24
2003May 19Sep 17May 19Oct 10
2002May 23Sep 21May 10Oct 11
2001May 20Oct 4May 6Oct 6
2000May 13Sep 21Apr 19Sep 21
1999May 16Sep 11May 6Oct 2
1998Jun 4Oct 5Apr 19Oct 19
1997no dataOct 8no dataOct 12
1996May 20Sep 18May 5Sep 23
1995May 24Sep 19May 13Sep 20
1994May 6Sep 21Apr 30Oct 22
1993May 9Sep 13Apr 30Sep 13
1992May 1Sep 7Apr 25Oct 7
1991May 3Sep 17Apr 30Sep 17
1990May 13Oct 6May 9Oct 7
1989no dataSep 11no dataOct 18
1988May 9Sep 19May 3Oct 20
1987May 4Sep 18Apr 22Oct 9
1986May 25no dataMay 17no data
1985May 13Sep 20May 13Sep 23
1984May 23Sep 23May 8Sep 24
1983Jun 1Sep 19May 15Sep 19
1982Jun 7Sep 12May 7Oct 6
1981May 14Sep 26May 12Sep 27
1980May 14Sep 22May 13Sep 22
1979May 31Sep 14May 11Oct 4
1978May 13Sep 14Apr 24Sep 19
1977May 29Sep 9May 5Oct 3
1976Jun 14Sep 9May 16Sep 28
1975May 29Sep 12May 1Sep 12
1974May 31Sep 3May 22Sep 13
1973Jun 4Sep 15May 14Sep 17
1972Jul 4Sep 21May 4Sep 24
1971May 20Sep 15May 19Sep 15
1970Jun 13Sep 10May 3Sep 10
1969Jun 14Sep 15Jun 14Oct 3
1968May 21Sep 17May 20Oct 3
1967May 17Sep 27May 11Oct 13
1966May 24Aug 22May 23Oct 1
1965May 27Aug 31May 27Sep 16
1964Jun 2Aug 20Jun 2Aug 30
1963May 22Oct 11May 22Oct 17
1962May 23Aug 28May 1Aug 28
1961May 8Sep 3May 8Sep 14
1960Jun 21Sep 9May 15Sep 30
1959Jun 1Sep 2May 14Sep 30
1958May 5Sep 15May 2Sep 21
1957May 23Sep 9Apr 29Oct 5
1956May 14Aug 31May 14Sep 6
1955May 29Sep 21Apr 28Sep 23
1954Jun 8Sep 19May 3Sep 19
1953Jun 25Sep 21May 14Sep 21
1952May 31Aug 31Apr 24Sep 14
1951Jun 9Sep 15Jun 3Sep 28

"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.