Last Frost Day

Frost history / Alliance 1WNW, NE

Alliance 1WNW, NE: frost dates by year

Last spring and first fall frost at NOAA station USC00250130, 1951 to 2017, measured from daily minimum temperatures.

Elevation 3,994 ft, 42.110, -102.897. Download the data (JSON), NOAA daily records

Summary at 32°F

Last spring frostFirst fall frost
MedianMay 13Sep 23
EarliestApr 21 (1977)Sep 9 (1962)
LatestJun 14 (1969)Oct 17 (1963)
Trendlittle change (less than half a day per decade)little change (less than half a day per decade)
Years with data4644

At 28°F (hard freeze) the median last spring date is Apr 30 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 291960197019801990200020101951: Jun 31952: May 111953: May 141954: May 31955: May 101956: May 141957: Apr 281958: Apr 301959: May 71960: May 201961: May 141962: May 11963: May 221964: May 241965: May 91966: May 241967: May 151968: May 201969: Jun 141970: May 21971: Apr 281972: May 31973: May 141974: May 311975: May 261977: Apr 211978: May 131979: May 121980: May 131981: May 141982: May 131983: May 171984: May 81985: Apr 271986: May 11990: May 111991: May 61994: May 22010: May 142011: May 32012: May 132013: May 62014: May 152015: May 212016: May 262017: May 20

First fall frost (32°F)

Aug 28Sep 12Sep 27Oct 12Oct 271960197019801990200020101951: Sep 221952: Oct 21953: Sep 211954: Sep 211955: Sep 231956: Oct 141957: Sep 221958: Sep 251959: Sep 291960: Sep 301961: Sep 141962: Sep 91963: Oct 171964: Sep 261965: Sep 161966: Sep 301967: Sep 271968: Oct 31969: Oct 41970: Sep 261971: Sep 191972: Sep 211973: Sep 161974: Sep 281975: Sep 201976: Sep 91977: Oct 101978: Sep 211979: Oct 41980: Sep 221981: Oct 41983: Sep 191984: Sep 231985: Sep 231988: Sep 141989: Sep 111990: Oct 71991: Sep 181994: Sep 222009: Sep 282012: Oct 42013: Oct 52014: Sep 122015: Oct 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
2017May 20no dataMay 4no data
2016May 26no dataMay 26no data
2015May 21Oct 13May 20Oct 25
2014May 15Sep 12May 15Oct 14
2013May 6Oct 5May 5Oct 12
2012May 13Oct 4Apr 17Oct 4
2011May 3no dataMay 2no data
2010May 14no dataApr 27no data
2009no dataSep 28no dataOct 7
1994May 2Sep 22Apr 30Oct 23
1991May 6Sep 18May 6Sep 18
1990May 11Oct 7May 10Oct 7
1989no dataSep 11no dataOct 18
1988no dataSep 14no dataSep 14
1986May 1no dataApr 16no data
1985Apr 27Sep 23Apr 8Sep 23
1984May 8Sep 23Apr 27Sep 24
1983May 17Sep 19May 13Sep 20
1982May 13no dataMay 13no data
1981May 14Oct 4May 14Oct 20
1980May 13Sep 22Apr 14Oct 11
1979May 12Oct 4May 11Oct 4
1978May 13Sep 21Apr 24Oct 6
1977Apr 21Oct 10Apr 13Oct 10
1976no dataSep 9no dataSep 28
1975May 26Sep 20Apr 14Oct 1
1974May 31Sep 28May 3Oct 6
1973May 14Sep 16May 3Oct 11
1972May 3Sep 21Apr 16Sep 21
1971Apr 28Sep 19Apr 28Sep 19
1970May 2Sep 26Apr 30Sep 26
1969Jun 14Oct 4Jun 2Oct 11
1968May 20Oct 3May 11Oct 9
1967May 15Sep 27May 11Sep 27
1966May 24Sep 30Apr 30Oct 1
1965May 9Sep 16Apr 6Sep 24
1964May 24Sep 26Apr 13Sep 26
1963May 22Oct 17Apr 23Oct 17
1962May 1Sep 9Apr 13Sep 9
1961May 14Sep 14Apr 28Sep 14
1960May 20Sep 30Apr 30Oct 19
1959May 7Sep 29Apr 25Sep 30
1958Apr 30Sep 25Apr 30Sep 30
1957Apr 28Sep 22Apr 13Oct 24
1956May 14Oct 14Apr 29Oct 20
1955May 10Sep 23Apr 28Oct 7
1954May 3Sep 21May 3Oct 14
1953May 14Sep 21May 13Oct 23
1952May 11Oct 2Apr 23Oct 5
1951Jun 3Sep 22Apr 22Sep 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.