Last Frost Day

Frost history / Hulett, WY

Hulett, WY: frost dates by year

Last spring and first fall frost at NOAA station USC00484760, 1951 to 2018, measured from daily minimum temperatures.

Elevation 3,758 ft, 44.686, -104.603. Download the data (JSON), NOAA daily records

Summary at 32°F

Last spring frostFirst fall frost
MedianMay 21Sep 17
EarliestApr 28 (2018)Aug 15 (1951)
LatestJun 30 (1995)Oct 16 (1963)
Trend1.6 days earlier per decade2.8 days later per decade
Years with data4642

At 28°F (hard freeze) the median last spring date is May 12 and the median first fall date is Sep 25.

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 141960197019801990200020101951: Jun 41952: May 281953: May 241954: May 251956: May 311957: Jun 151958: Jun 261959: May 231960: May 201961: May 71962: May 11963: May 231964: Jun 21965: May 271966: May 191967: May 131968: May 211969: Jun 151970: May 141971: May 201972: May 41973: May 221975: May 291992: May 281993: Jun 41994: May 51995: Jun 301998: May 71999: May 172000: Jun 22001: May 242002: May 252003: May 202004: May 142005: May 292006: May 142007: May 242008: May 112009: May 162010: May 152011: May 142014: May 152015: May 212016: May 172017: May 212018: Apr 28

First fall frost (32°F)

Jul 29Aug 13Aug 28Sep 12Sep 27Oct 12Oct 271960197019801990200020101951: Aug 151952: Sep 21953: Sep 101955: Sep 111956: Sep 61957: Sep 91958: Sep 151959: Sep 21960: Sep 91961: Sep 141962: Sep 41963: Oct 161964: Sep 121965: Sep 51966: Oct 11967: Sep 271968: Sep 231969: Sep 231970: Sep 101971: Sep 151972: Sep 211991: Sep 181992: Aug 301993: Aug 311994: Sep 221998: Oct 61999: Sep 132000: Sep 232002: Sep 222003: Sep 302004: Oct 12005: Oct 52006: Sep 192007: Sep 102008: Sep 32009: Sep 232010: Oct 132011: Sep 212014: Sep 112015: Oct 152016: Oct 52017: Oct 3

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
2018Apr 28no dataApr 26no data
2017May 21Oct 3Apr 30Oct 4
2016May 17Oct 5May 15Oct 6
2015May 21Oct 15May 11Oct 15
2014May 15Sep 11May 15Oct 3
2011May 14Sep 21May 5Oct 19
2010May 15Oct 13May 14Oct 13
2009May 16Sep 23May 16Sep 28
2008May 11Sep 3May 5Sep 24
2007May 24Sep 10Apr 14Sep 14
2006May 14Sep 19May 5Sep 19
2005May 29Oct 5May 12Oct 5
2004May 14Oct 1May 14Oct 2
2003May 20Sep 30May 20Sep 30
2002May 25Sep 22May 25Sep 22
2001May 24no dataApr 23no data
2000Jun 2Sep 23May 18Sep 24
1999May 17Sep 13May 12Sep 29
1998May 7Oct 6May 7Oct 12
1995Jun 30no dataApr 28no data
1994May 5Sep 22Apr 30Oct 22
1993Jun 4Aug 31May 2Sep 14
1992May 28Aug 30May 27Sep 14
1991no dataSep 18no dataSep 18
1975May 29no dataApr 20no data
1973May 22no dataMay 14no data
1972May 4Sep 21Apr 24Sep 21
1971May 20Sep 15May 20Sep 23
1970May 14Sep 10May 1Sep 26
1969Jun 15Sep 23May 22Oct 5
1968May 21Sep 23May 20Oct 3
1967May 13Sep 27May 11Sep 27
1966May 19Oct 1May 19Oct 10
1965May 27Sep 5Apr 27Sep 16
1964Jun 2Sep 12Apr 29Sep 27
1963May 23Oct 16May 22Oct 27
1962May 1Sep 4May 1Sep 4
1961May 7Sep 14May 7Sep 14
1960May 20Sep 9May 20Sep 30
1959May 23Sep 2May 12Sep 10
1958Jun 26Sep 15Jun 25Sep 16
1957Jun 15Sep 9May 23Sep 19
1956May 31Sep 6May 3Sep 6
1955no dataSep 11no dataSep 11
1954May 25no dataMay 12no data
1953May 24Sep 10May 15Sep 20
1952May 28Sep 2May 11Sep 14
1951Jun 4Aug 15Jun 4Aug 24

"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.