Last Frost Day

Frost history / Mandan Exp Stn, ND

Mandan Exp Stn, ND: frost dates by year

Last spring and first fall frost at NOAA station USC00325479, 1951 to 2025, measured from daily minimum temperatures.

Elevation 1,750 ft, 46.813, -100.910. Download the data (JSON), NOAA daily records

Summary at 32°F

Last spring frostFirst fall frost
MedianMay 13Sep 22
EarliestApr 14 (2007)Sep 3 (1974)
LatestJun 20 (1969)Oct 20 (2021)
Trend0.9 days earlier per decade2.1 days later per decade
Years with data7168

At 28°F (hard freeze) the median last spring date is May 6 and the median first fall date is Oct 2.

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: May 111952: May 121953: May 141954: May 171955: May 81956: May 41957: May 91958: May 221959: May 231960: May 111961: May 261962: Apr 231963: May 221964: May 311965: May 281966: May 131967: May 131968: May 211969: Jun 201970: May 71971: May 201972: May 91973: May 171974: May 241975: May 21976: May 71977: May 21978: Apr 251979: May 121980: May 141981: May 141982: May 91983: May 201984: May 261985: Apr 271986: May 171987: May 221988: May 131989: May 61990: May 101991: May 71992: May 261993: May 201994: May 71995: May 171996: May 111997: May 201998: Jun 41999: Apr 232000: May 142001: Apr 242002: May 242003: May 202004: May 142005: May 152006: May 132007: Apr 142008: May 112009: May 162011: May 22012: May 312013: May 122014: May 172015: May 202016: May 172017: May 12018: May 102019: May 92023: May 22024: May 42025: Apr 29

First fall frost (32°F)

Aug 28Sep 12Sep 27Oct 12Oct 2719601970198019902000201020201951: Sep 221952: Sep 221953: Sep 211954: Sep 211955: Sep 101956: Sep 61957: Sep 261958: Sep 301959: Sep 101960: Sep 171961: Sep 241962: Sep 101963: Oct 111964: Sep 111965: Sep 51966: Sep 141967: Sep 271968: Oct 41969: Oct 51970: Sep 131971: Sep 211972: Sep 211973: Sep 161974: Sep 31975: Sep 131976: Sep 91977: Oct 21978: Sep 211979: Sep 211980: Oct 111981: Sep 161982: Sep 151983: Sep 211984: Sep 151985: Sep 241986: Oct 111987: Oct 21988: Oct 41989: Sep 111990: Sep 231991: Sep 181992: Sep 281993: Sep 141995: Sep 201996: Sep 251997: Sep 201998: Oct 11999: Sep 272000: Sep 232001: Oct 42002: Sep 262003: Sep 192004: Sep 282005: Oct 52006: Sep 202007: Oct 82008: Oct 92009: Oct 62010: Sep 172011: Sep 142012: Sep 222013: Oct 52014: Sep 152015: Sep 292016: Oct 62019: Oct 22021: Oct 202024: 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
2025Apr 29no dataApr 29no data
2024May 4Oct 13Apr 24Oct 14
2023May 2no dataMay 2no data
2021no dataOct 20no dataOct 20
2019May 9Oct 2May 9Oct 10
2018May 10no dataApr 20no data
2017May 1no dataApr 29no data
2016May 17Oct 6Apr 13Oct 8
2015May 20Sep 29May 19Oct 16
2014May 17Sep 15May 15Oct 4
2013May 12Oct 5May 12Oct 6
2012May 31Sep 22Apr 17Sep 22
2011May 2Sep 14May 1Sep 14
2010no dataSep 17no dataOct 2
2009May 16Oct 6May 16Oct 9
2008May 11Oct 9May 3Oct 18
2007Apr 14Oct 8Apr 14Oct 12
2006May 13Sep 20May 12Oct 10
2005May 15Oct 5May 15Oct 6
2004May 14Sep 28May 14Oct 1
2003May 20Sep 19Apr 17Sep 30
2002May 24Sep 26May 24Oct 2
2001Apr 24Oct 4Apr 23Oct 5
2000May 14Sep 23Apr 20Sep 24
1999Apr 23Sep 27Apr 18Oct 1
1998Jun 4Oct 1Apr 17Oct 1
1997May 20Sep 20May 20Sep 20
1996May 11Sep 25May 10Oct 18
1995May 17Sep 20Apr 27Sep 20
1994May 7no dataMay 2no data
1993May 20Sep 14Apr 30Sep 14
1992May 26Sep 28Apr 26Sep 28
1991May 7Sep 18May 7Sep 19
1990May 10Sep 23May 10Oct 7
1989May 6Sep 11May 6Sep 12
1988May 13Oct 4Apr 28Oct 4
1987May 22Oct 2Apr 21Oct 2
1986May 17Oct 11Apr 21Oct 12
1985Apr 27Sep 24Apr 26Sep 24
1984May 26Sep 15May 26Sep 25
1983May 20Sep 21May 16Sep 21
1982May 9Sep 15May 8Oct 6
1981May 14Sep 16May 10Oct 14
1980May 14Oct 11May 14Oct 12
1979May 12Sep 21May 10Oct 4
1978Apr 25Sep 21Apr 21Oct 7
1977May 2Oct 2Apr 24Oct 2
1976May 7Sep 9May 7Sep 23
1975May 2Sep 13May 1Oct 25
1974May 24Sep 3May 24Sep 28
1973May 17Sep 16May 14Sep 16
1972May 9Sep 21May 6Oct 6
1971May 20Sep 21May 2Sep 22
1970May 7Sep 13Apr 23Sep 13
1969Jun 20Oct 5Jun 2Oct 8
1968May 21Oct 4May 20Oct 4
1967May 13Sep 27May 12Sep 27
1966May 13Sep 14May 13Oct 5
1965May 28Sep 5May 28Sep 20
1964May 31Sep 11Apr 18Sep 11
1963May 22Oct 11May 22Oct 27
1962Apr 23Sep 10Apr 16Oct 20
1961May 26Sep 24May 9Sep 28
1960May 11Sep 17May 11Sep 30
1959May 23Sep 10May 15Sep 10
1958May 22Sep 30Apr 29Sep 30
1957May 9Sep 26Apr 16Sep 26
1956May 4Sep 6May 4Sep 29
1955May 8Sep 10May 8Sep 11
1954May 17Sep 21May 9Oct 2
1953May 14Sep 21May 14Oct 6
1952May 12Sep 22May 11Oct 2
1951May 11Sep 22Apr 25Sep 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.