Last Frost Day

Frost history / Evanston 1 E, WY

Evanston 1 E, WY: frost dates by year

Last spring and first fall frost at NOAA station USC00483100, 1951 to 2025, measured from daily minimum temperatures.

Elevation 6,825 ft, 41.265, -110.951. Download the data (JSON), NOAA daily records

Summary at 32°F

Last spring frostFirst fall frost
MedianJun 21Sep 3
EarliestMay 11 (1992)Aug 2 (1975)
LatestJul 31 (1995)Oct 3 (1990)
Trend3.3 days earlier per decade3.2 days later per decade
Years with data6159

At 28°F (hard freeze) the median last spring date is Jun 2 and the median first fall date is Sep 15.

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 30May 15May 30Jun 14Jun 29Jul 14Jul 29Aug 1319601970198019902000201020201951: Jul 131953: Jun 271954: Jul 221955: Jul 131956: Jun 191957: Jul 241958: Jun 301959: Jul 91960: Jun 221961: May 171962: Jun 161963: Jul 271964: Jun 201965: Jun 291966: Jun 251967: Jul 11968: Jul 11969: Jun 291970: Jun 301971: Jun 301972: Jun 261973: Jun 201974: Jul 41975: Jun 281976: Jul 41977: May 301978: Jun 261979: Jun 151980: Jun 161981: Jun 151982: Jun 101983: Jul 101986: May 231987: Jul 191988: Jun 21989: Jun 221990: Jun 151991: Jun 201992: May 111993: Jun 241994: Jun 171995: Jul 311996: May 311997: Jun 251998: Jun 181999: May 202000: Jun 172002: Jun 122003: May 202004: May 302005: Jun 142007: Jun 182009: May 162014: Jun 182017: Jun 222019: Jun 212020: Jun 182021: Jun 102022: Jun 212024: Jun 182025: Jun 23

First fall frost (32°F)

Jul 14Jul 29Aug 13Aug 28Sep 12Sep 27Oct 1219601970198019902000201020201951: Aug 251952: Sep 11953: Aug 111954: Aug 171955: Sep 91956: Aug 81957: Sep 51958: Sep 151959: Aug 141960: Aug 161961: Sep 31962: Aug 231963: Sep 251964: Aug 201965: Aug 211966: Aug 211968: Aug 161969: Sep 51970: Sep 91971: Sep 41972: Aug 241973: Sep 21974: Aug 101975: Aug 21976: Aug 271977: Aug 311978: Aug 151979: Sep 111980: Aug 41981: Sep 11982: Sep 121985: Sep 121986: Sep 111987: Sep 61988: Sep 121989: Aug 251990: Oct 31991: Sep 151992: Aug 241993: Aug 301994: Sep 151995: Sep 211996: Sep 171998: Aug 21999: Sep 32001: Sep 82002: Sep 112003: Sep 132004: Aug 272005: Aug 312006: Sep 162007: Sep 172008: Sep 22015: Sep 62018: Sep 212020: Sep 12023: Sep 232024: Sep 132025: Sep 24

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
2025Jun 23Sep 24May 20Oct 7
2024Jun 18Sep 13Jun 18Oct 1
2023no dataSep 23no dataSep 24
2022Jun 21no dataMay 23no data
2021Jun 10no dataJun 10no data
2020Jun 18Sep 1Jun 9Sep 8
2019Jun 21no dataJun 9no data
2018no dataSep 21no dataSep 25
2017Jun 22no dataMay 21no data
2015no dataSep 6no dataOct 27
2014Jun 18no dataMay 17no data
2009May 16no dataMay 16no data
2008no dataSep 2no dataOct 10
2007Jun 18Sep 17May 30Sep 25
2006no dataSep 16no dataSep 17
2005Jun 14Aug 31Jun 8Sep 18
2004May 30Aug 27May 15Sep 19
2003May 20Sep 13May 19Sep 14
2002Jun 12Sep 11Jun 11Oct 12
2001no dataSep 8no dataSep 8
2000Jun 17no dataJun 2no data
1999May 20Sep 3May 17Sep 5
1998Jun 18Aug 2Jun 18Oct 5
1997Jun 25no dataMay 9no data
1996May 31Sep 17May 24Sep 23
1995Jul 31Sep 21Jun 8Sep 21
1994Jun 17Sep 15May 22Sep 22
1993Jun 24Aug 30Jun 13Sep 13
1992May 11Aug 24May 1Aug 26
1991Jun 20Sep 15May 19Sep 15
1990Jun 15Oct 3May 25Oct 7
1989Jun 22Aug 25Jun 21Sep 13
1988Jun 2Sep 12May 19Sep 19
1987Jul 19Sep 6May 4Sep 6
1986May 23Sep 11May 23Sep 17
1985no dataSep 12no dataSep 19
1983Jul 10no dataJul 2no data
1982Jun 10Sep 12Jun 9Sep 29
1981Jun 15Sep 1Jun 15Sep 26
1980Jun 16Aug 4May 27Sep 22
1979Jun 15Sep 11Jun 9Sep 12
1978Jun 26Aug 15Jun 1Sep 18
1977May 30Aug 31May 30Sep 18
1976Jul 4Aug 27Jun 27Aug 27
1975Jun 28Aug 2May 26Aug 25
1974Jul 4Aug 10Jun 9Aug 21
1973Jun 20Sep 2Jun 19Sep 22
1972Jun 26Aug 24May 27Sep 13
1971Jun 30Sep 4Jun 30Sep 15
1970Jun 30Sep 9May 31Sep 10
1969Jun 29Sep 5Jun 18Sep 23
1968Jul 1Aug 16Jun 30Sep 4
1967Jul 1no dataMay 14no data
1966Jun 25Aug 21Jun 25Oct 1
1965Jun 29Aug 21May 27Aug 31
1964Jun 20Aug 20May 18Aug 20
1963Jul 27Sep 25May 17Oct 14
1962Jun 16Aug 23Jun 7Aug 31
1961May 17Sep 3May 17Sep 3
1960Jun 22Aug 16Jun 21Aug 25
1959Jul 9Aug 14Jul 8Aug 31
1958Jun 30Sep 15Jun 4Sep 16
1957Jul 24Sep 5Jun 17Sep 8
1956Jun 19Aug 8May 15Aug 27
1955Jul 13Sep 9Jul 8Sep 13
1954Jul 22Aug 17Jun 29Aug 23
1953Jun 27Aug 11Jun 25Sep 3
1952no dataSep 1no dataSep 1
1951Jul 13Aug 25Jun 8Aug 25

"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.