Last Frost Day

Frost history / Grand Forks Intl Ap, ND

Grand Forks Intl Ap, ND: frost dates by year

Last spring and first fall frost at NOAA station USW00014916, 1951 to 2024, measured from daily minimum temperatures.

Elevation 842 ft, 47.943, -97.184. Download the data (JSON), NOAA daily records

Summary at 32°F

Last spring frostFirst fall frost
MedianMay 15Sep 24
EarliestApr 16 (1985)Aug 20 (2004)
LatestJul 3 (1972)Oct 27 (1963)
Trend0.8 days earlier per decade2.0 days later per decade
Years with data7373

At 28°F (hard freeze) the median last spring date is May 3 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 29Jul 1419601970198019902000201020201951: May 101952: May 161953: Jun 61954: May 251955: May 81956: May 151957: May 271958: May 221959: May 231960: May 111961: May 291962: May 61963: May 231964: Jun 11965: May 271966: May 101967: May 211968: May 231969: Jun 201970: May 51971: May 201972: Jul 31973: May 171974: May 151975: May 151976: May 171977: May 21978: Apr 211979: May 151980: May 151981: May 101982: May 81983: May 251984: May 261985: Apr 161986: May 21987: Apr 221988: May 161989: May 61990: May 181991: May 51992: May 41993: May 21994: May 121996: May 111997: May 201998: May 31999: May 92000: May 152001: Apr 242002: May 242003: May 202004: May 142005: May 152006: May 212007: May 252008: May 272009: Jun 62010: May 92011: May 262012: May 92013: May 122014: May 162015: May 302016: May 142017: May 192018: May 112019: May 172020: May 302021: May 282022: May 212023: May 22024: Apr 24

First fall frost (32°F)

Aug 13Aug 28Sep 12Sep 27Oct 12Oct 27Nov 1119601970198019902000201020201951: Sep 231952: Sep 191953: Sep 221954: Sep 211955: Sep 101956: Sep 61957: Sep 231958: Sep 301959: Sep 101960: Sep 131961: Sep 271962: Sep 191963: Oct 271964: Sep 111965: Aug 281966: Sep 251967: Sep 261968: Sep 281969: Sep 301970: Sep 131971: Sep 211972: Sep 261973: Sep 161974: Sep 11975: Sep 81976: Sep 231977: Oct 11978: Oct 71979: Sep 71980: Sep 271981: Sep 171982: Aug 271983: Sep 231984: Sep 111985: Sep 241986: Aug 281987: Sep 251988: Sep 61989: Sep 221990: Sep 161991: Sep 261992: Sep 221993: Sep 281994: Oct 241995: Sep 201996: Sep 251998: Sep 301999: Sep 192000: Sep 152001: Sep 242002: Sep 292003: Sep 252004: Aug 202005: Oct 52006: Sep 202007: Sep 282008: Oct 32009: Sep 292010: Oct 22011: Sep 152012: Sep 142013: Oct 152014: Oct 42015: Sep 292016: Oct 82017: Oct 62018: Sep 282019: Oct 102020: Sep 82021: Oct 172022: Sep 272023: Oct 82024: Oct 14

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

"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.