Last Frost Day

Frost history / Basin, WY

Basin, WY: frost dates by year

Last spring and first fall frost at NOAA station USC00480540, 1951 to 2025, measured from daily minimum temperatures.

Elevation 3,840 ft, 44.380, -108.035. Download the data (JSON), NOAA daily records

Summary at 32°F

Last spring frostFirst fall frost
MedianMay 11Sep 22
EarliestApr 6 (2016)Sep 2 (1974)
LatestJun 20 (1978)Oct 28 (2015)
Trend1.3 days earlier per decade1.8 days later per decade
Years with data7472

At 28°F (hard freeze) the median last spring date is Apr 30 and the median first fall date is Oct 6.

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 14Jun 2919601970198019902000201020201951: Jun 31952: May 101953: May 151954: May 291955: Apr 291956: May 41957: Apr 271958: May 11959: May 71960: May 151961: May 81962: May 11963: May 21964: May 31965: May 271966: May 231967: May 121968: May 201969: May 81970: May 131971: Apr 141972: May 111973: May 281974: May 221975: May 261976: May 11977: May 201978: Jun 201979: May 101980: May 141981: May 121982: Jun 71983: Jun 11984: May 171985: May 141986: May 171987: Apr 211988: May 71989: May 11990: May 101991: May 51992: May 21993: Apr 241994: May 21995: May 141996: May 111997: May 191998: Apr 281999: May 112000: May 132001: May 202002: May 232003: May 192004: May 132005: May 122006: May 112007: May 62008: May 22009: May 72010: May 122011: May 42012: May 72013: May 32014: May 132015: May 112016: Apr 62017: Apr 102018: Apr 252019: May 122020: May 82021: May 102022: Apr 302023: Apr 282024: May 24

First fall frost (32°F)

Aug 28Sep 12Sep 27Oct 12Oct 27Nov 1119601970198019902000201020201951: Sep 121952: Sep 141953: Sep 211954: Oct 31955: Sep 221956: Sep 221957: Sep 191958: Sep 251959: Sep 281960: Oct 151961: Sep 141962: Sep 41963: Oct 171964: Sep 271965: Sep 51966: Sep 301967: Oct 41968: Sep 221969: Oct 71970: Sep 101971: Sep 161972: Sep 211973: Sep 151974: Sep 21975: Sep 191976: Sep 91977: Sep 131978: Sep 181979: Sep 141980: Sep 221981: Oct 11982: Sep 141985: Sep 231986: Sep 221987: Sep 181988: Sep 291989: Sep 111990: Oct 31991: Sep 181992: Sep 141993: Sep 141994: Oct 81995: Sep 211996: Sep 231997: Oct 91998: Oct 111999: Sep 132000: Sep 202001: Oct 42002: Sep 212003: Sep 172004: Oct 162005: Sep 252006: Oct 92007: Sep 92008: Oct 82010: Sep 32011: Sep 202012: Sep 122013: Sep 282014: Sep 122015: Oct 282016: Oct 122017: Oct 42018: Oct 112019: Oct 102020: Sep 92021: Oct 122022: Oct 172023: Oct 142024: Oct 12025: Oct 6

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
2025no dataOct 6no dataOct 18
2024May 24Oct 1Apr 18Oct 19
2023Apr 28Oct 14Apr 28Oct 26
2022Apr 30Oct 17Apr 30Oct 17
2021May 10Oct 12Apr 22Oct 12
2020May 8Sep 9Apr 18Oct 8
2019May 12Oct 10May 2Oct 10
2018Apr 25Oct 11Apr 14Oct 14
2017Apr 10Oct 4Mar 11Oct 27
2016Apr 6Oct 12Mar 27Oct 12
2015May 11Oct 28May 11Oct 28
2014May 13Sep 12May 13Oct 3
2013May 3Sep 28May 2Oct 5
2012May 7Sep 12May 6Oct 5
2011May 4Sep 20May 1Oct 18
2010May 12Sep 3May 7Oct 19
2009May 7no dataApr 9no data
2008May 2Oct 8May 2Oct 11
2007May 6Sep 9Apr 13Oct 21
2006May 11Oct 9May 9Oct 17
2005May 12Sep 25May 1Oct 22
2004May 13Oct 16Apr 29Oct 24
2003May 19Sep 17May 19Oct 13
2002May 23Sep 21May 23Oct 2
2001May 20Oct 4May 6Oct 4
2000May 13Sep 20May 1Sep 22
1999May 11Sep 13May 6Sep 28
1998Apr 28Oct 11Apr 18Oct 19
1997May 19Oct 9Apr 23Oct 13
1996May 11Sep 23May 5Sep 27
1995May 14Sep 21Apr 27Sep 21
1994May 2Oct 8May 2Oct 23
1993Apr 24Sep 14Apr 21Sep 14
1992May 2Sep 14Apr 25Oct 7
1991May 5Sep 18May 1Oct 5
1990May 10Oct 3May 2Oct 3
1989May 1Sep 11May 1Oct 18
1988May 7Sep 29Apr 26Oct 18
1987Apr 21Sep 18Apr 10Oct 10
1986May 17Sep 22Apr 30Oct 12
1985May 14Sep 23May 13Sep 24
1984May 17no dataMay 17no data
1983Jun 1no dataMay 17no data
1982Jun 7Sep 14May 6Oct 10
1981May 12Oct 1May 8Oct 6
1980May 14Sep 22Apr 17Oct 10
1979May 10Sep 14Apr 27Oct 4
1978Jun 20Sep 18May 9Sep 19
1977May 20Sep 13May 5Oct 2
1976May 1Sep 9Apr 30Oct 5
1975May 26Sep 19May 1Sep 28
1974May 22Sep 2May 16Sep 13
1973May 28Sep 15Apr 22Oct 4
1972May 11Sep 21May 2Sep 26
1971Apr 14Sep 16Apr 14Sep 18
1970May 13Sep 10Apr 30Sep 25
1969May 8Oct 7Mar 31Oct 7
1968May 20Sep 22May 11Oct 8
1967May 12Oct 4May 4Oct 4
1966May 23Sep 30May 23Oct 1
1965May 27Sep 5Apr 27Sep 16
1964May 3Sep 27Apr 22Sep 27
1963May 2Oct 17Apr 25Oct 27
1962May 1Sep 4Apr 30Oct 1
1961May 8Sep 14May 6Sep 24
1960May 15Oct 15May 1Oct 15
1959May 7Sep 28Apr 25Sep 30
1958May 1Sep 25Apr 30Oct 10
1957Apr 27Sep 19Apr 27Oct 5
1956May 4Sep 22Apr 19Oct 14
1955Apr 29Sep 22Apr 28Sep 23
1954May 29Oct 3May 3Oct 4
1953May 15Sep 21May 14Oct 4
1952May 10Sep 14Apr 22Oct 6
1951Jun 3Sep 12Apr 23Sep 27

"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.