Last Frost Day

Frost history / Alton, UT

Alton, UT: frost dates by year

Last spring and first fall frost at NOAA station USC00420086, 1951 to 2025, measured from daily minimum temperatures.

Elevation 7,098 ft, 37.440, -112.482. Download the data (JSON), NOAA daily records

Summary at 32°F

Last spring frostFirst fall frost
MedianJun 4Sep 24
EarliestMay 9 (2023)Aug 23 (1968)
LatestJun 26 (1985)Oct 28 (2015)
Trend0.9 days earlier per decade1.6 days later per decade
Years with data7271

At 28°F (hard freeze) the median last spring date is May 22 and the median first fall date is Oct 9.

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 1419601970198019902000201020201951: Jun 41952: May 221953: Jun 21954: Jun 101956: May 301957: May 251958: May 141959: May 301960: May 251961: Jun 31962: Jun 171963: Jun 81964: Jun 181965: Jun 181966: Jun 41967: Jun 101968: Jun 71969: Jun 101970: Jun 151971: Jun 61972: May 231973: Jun 161974: May 221975: Jun 261976: Jun 141977: May 261978: May 261979: Jun 191980: Jun 71981: Jun 161982: Jun 141983: Jun 21985: Jun 261986: May 231987: May 301988: Jun 81989: May 301990: Jun 21991: Jun 251992: Jun 161993: Jun 81994: May 231995: Jun 181996: May 281997: May 271998: Jun 171999: Jun 52000: May 172001: Jun 142002: May 252003: May 122004: Jun 102005: Jun 82006: May 302007: Jun 82008: Jun 132009: Jun 62011: Jun 82012: May 292013: Jun 12014: May 222015: May 222016: May 252017: Jun 132018: May 272019: May 282020: Jun 92021: May 262022: May 312023: May 92024: May 222025: Jun 5

First fall frost (32°F)

Aug 13Aug 28Sep 12Sep 27Oct 12Oct 27Nov 1119601970198019902000201020201951: Sep 221952: Sep 121953: Sep 281954: Sep 261955: Sep 211956: Oct 91957: Sep 211958: Sep 251959: Sep 161960: Oct 101961: Sep 41962: Oct 51963: Oct 131964: Sep 31965: Sep 91966: Sep 151967: Oct 71968: Aug 231969: Oct 31970: Sep 61971: Sep 181972: Sep 301973: Sep 21974: Sep 281975: Sep 241976: Oct 91977: Sep 171978: Sep 181979: Oct 211980: Sep 231981: Oct 91982: Sep 141983: Sep 201984: Oct 21985: Sep 121986: Sep 111987: Oct 151988: Sep 131989: Aug 251990: Oct 81991: Oct 211992: Sep 131995: Sep 221996: Sep 171997: Oct 81998: Oct 11999: Sep 292000: Sep 242001: Sep 92002: Oct 22003: Sep 192004: Sep 52005: Sep 132007: Sep 242009: Oct 12010: Oct 82011: Oct 62012: Oct 162013: Sep 272014: Oct 22015: Oct 282016: Sep 232017: Sep 232018: Oct 92019: Sep 302020: Sep 92021: Oct 112022: Oct 202023: Oct 32024: Oct 182025: Sep 13

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

"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.