Last Frost Day

Frost history / Hill City 1 W, ID

Hill City 1 W, ID: frost dates by year

Last spring and first fall frost at NOAA station USC00104268, 1951 to 2005, measured from daily minimum temperatures.

Elevation 5,100 ft, 43.299, -115.073. Download the data (JSON), NOAA daily records

Summary at 32°F

Last spring frostFirst fall frost
MedianJun 29Aug 28
EarliestMay 18 (1965)Aug 1 (1975)
LatestJul 31 (1995)Oct 3 (1990)
Trendlittle change (less than half a day per decade)1.3 days later per decade
Years with data5452

At 28°F (hard freeze) the median last spring date is Jun 13 and the median first fall date is Sep 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 14Jul 29Aug 13196019701980199020001951: Jun 231952: Jun 171953: Jun 251954: Jul 241955: Jul 81956: Jul 11957: Jun 171958: Jun 291959: Jul 91960: Jun 211961: Jun 31962: Jul 201963: Jun 301964: Jun 221965: May 181966: Jul 31967: Jun 121968: Jul 21969: Jun 301970: Jun 301971: Jul 41972: Jul 231973: Jul 21974: Jul 121975: Jun 281976: Jul 31977: Jul 141978: Jun 261980: Jun 271981: Jul 151982: Jun 101983: Jul 211984: Jul 11985: Jun 271986: Jul 171987: Jul 191988: Jul 71989: Jun 251990: Jul 41991: Jun 211992: Jun 141993: Jul 181994: Jun 171995: Jul 311996: Jun 231997: Jul 111998: Jun 271999: Jul 92000: Jun 172001: Jun 162002: Jun 202003: Jun 232004: Jun 122005: Jun 19

First fall frost (32°F)

Jul 14Jul 29Aug 13Aug 28Sep 12Sep 27Oct 12196019701980199020001951: Aug 251952: Sep 11953: Aug 251954: Aug 181955: Sep 111956: Aug 31957: Sep 91958: Sep 31959: Aug 141960: Aug 231961: Sep 31962: Aug 241963: Aug 261964: Aug 201965: Aug 301966: Aug 221967: Sep 121968: Sep 31969: Aug 301970: Sep 91971: Aug 241972: Sep 71973: Aug 261974: Aug 81975: Aug 11976: Aug 261977: Aug 301979: Sep 131980: Aug 51981: Sep 11983: Sep 101984: Sep 21985: Aug 101986: Sep 111987: Aug 161988: Aug 231989: Aug 251990: Oct 31991: Sep 151992: Aug 231993: Aug 171994: Aug 311995: Aug 91996: Aug 191997: Sep 171998: Sep 201999: Aug 312001: Sep 82002: Aug 222003: Sep 92004: Aug 272005: Aug 31

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

"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.