Last Frost Day

Frost history / Emblem, WY

Emblem, WY: frost dates by year

Last spring and first fall frost at NOAA station USC00483031, 1962 to 2024, measured from daily minimum temperatures.

Elevation 4,448 ft, 44.497, -108.391. Download the data (JSON), NOAA daily records

Summary at 32°F

Last spring frostFirst fall frost
MedianMay 13Sep 22
EarliestApr 21 (1987)Aug 23 (2015)
LatestJun 23 (2017)Oct 21 (1963)
Trend0.8 days later per decade1.6 days later per decade
Years with data6163

At 28°F (hard freeze) the median last spring date is May 2 and the median first fall date is Oct 5.

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 291970198019902000201020201963: May 31964: May 111965: May 181966: May 231967: May 131968: May 201969: May 211970: May 141971: Apr 271972: May 31973: May 121974: May 161975: May 261976: May 11977: May 51978: May 91979: Jun 81980: May 131981: May 121982: May 301983: May 151984: May 81985: May 131986: May 231987: Apr 211988: May 41989: May 261990: May 161991: May 41992: May 111993: Apr 251994: Apr 301995: May 141997: May 191998: Apr 221999: May 172000: May 132001: May 212002: May 242003: May 202004: May 152005: May 142006: May 102007: May 72008: Jun 112009: Jun 72010: May 252011: May 62012: May 262013: May 32014: May 132015: May 112016: May 122017: Jun 232018: Apr 262019: May 192020: May 82021: May 212022: May 232023: Apr 262024: May 24

First fall frost (32°F)

Aug 13Aug 28Sep 12Sep 27Oct 12Oct 271970198019902000201020201962: Sep 41963: Oct 211964: Sep 111965: Sep 51966: Oct 11967: Oct 41968: Sep 171969: Oct 21970: Sep 121971: Sep 171972: Sep 211973: Sep 151974: Sep 21975: Sep 191976: Sep 91977: Oct 21978: Sep 181979: Sep 141980: Sep 161981: Sep 261982: Sep 141983: Sep 191984: Sep 241985: Sep 231986: Sep 271987: Sep 281988: Sep 191989: Sep 111990: Oct 31991: Sep 181992: Sep 141993: Sep 141994: Sep 221995: Sep 201996: Sep 261997: Oct 61998: Oct 111999: Sep 132000: Sep 222001: Oct 52002: Sep 222003: Sep 132004: Sep 152005: Oct 42006: Oct 92007: Sep 102008: Sep 82009: Sep 282010: Oct 122011: Sep 212012: Oct 42013: Oct 32014: Sep 122015: Aug 232016: Oct 62017: Oct 32018: Sep 262019: Oct 12020: Sep 102021: Sep 292022: Oct 142023: Oct 72024: Oct 1

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

"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.