Last Frost Day

Frost history / Butte 5SE, ND

Butte 5SE, ND: frost dates by year

Last spring and first fall frost at NOAA station USC00321225, 1951 to 2017, measured from daily minimum temperatures.

Elevation 1,720 ft, 47.795, -100.585. Download the data (JSON), NOAA daily records

Summary at 32°F

Last spring frostFirst fall frost
MedianMay 15Sep 23
EarliestApr 21 (1978)Sep 4 (1962)
LatestJun 12 (1969)Oct 27 (1963)
Trend0.8 days earlier per decade2.0 days later per decade
Years with data4443

At 28°F (hard freeze) the median last spring date is May 8 and the median first fall date is Oct 4.

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: May 101952: May 171953: May 151955: May 81958: May 221959: May 271960: May 71961: May 171962: Jun 11963: May 221965: May 281967: May 131968: May 201969: Jun 121970: May 211971: May 191972: May 91973: May 161974: May 171975: May 11976: May 71977: May 71978: Apr 211979: May 121980: May 121981: May 101983: May 161984: May 71988: May 161989: May 61990: May 141991: May 71992: May 231993: May 161994: May 51995: May 231996: May 111997: May 211998: May 72012: Apr 262013: May 122015: May 292016: May 152017: May 19

First fall frost (32°F)

Aug 28Sep 12Sep 27Oct 12Oct 27Nov 111960197019801990200020101951: Sep 151953: Sep 211954: Sep 211955: Sep 101958: Sep 251959: Sep 101960: Sep 301961: Sep 111962: Sep 41963: Oct 271964: Sep 111966: Sep 251967: Sep 271968: Oct 31969: Oct 81970: Sep 131972: Sep 211973: Sep 161974: Sep 211975: Sep 121976: Sep 231977: Oct 11978: Oct 71979: Oct 41980: Oct 111981: Oct 141982: Sep 151983: Sep 211986: Sep 61987: Oct 21988: Oct 31989: Sep 121990: Oct 61991: Sep 181992: Sep 221993: Sep 141994: Oct 11995: Sep 201996: Sep 291997: Oct 101998: Oct 12013: Oct 52014: Oct 2

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 19no dataMay 19no data
2016May 15no dataMay 1no data
2015May 29no dataMay 19no data
2014no dataOct 2no dataOct 3
2013May 12Oct 5May 12Oct 20
2012Apr 26no dataApr 17no data
1998May 7Oct 1Apr 16Oct 13
1997May 21Oct 10May 21Oct 13
1996May 11Sep 29May 10Oct 2
1995May 23Sep 20Apr 26Sep 21
1994May 5Oct 1May 5Oct 24
1993May 16Sep 14May 1Oct 2
1992May 23Sep 22May 23Sep 22
1991May 7Sep 18May 7Sep 19
1990May 14Oct 6May 9Oct 7
1989May 6Sep 12May 6Sep 23
1988May 16Oct 3May 5Oct 3
1987no dataOct 2no dataOct 2
1986no dataSep 6no dataOct 11
1984May 7no dataMay 2no data
1983May 16Sep 21May 16Sep 22
1982no dataSep 15no dataSep 15
1981May 10Oct 14May 9Oct 21
1980May 12Oct 11May 11Oct 12
1979May 12Oct 4May 10Oct 12
1978Apr 21Oct 7Apr 21Oct 13
1977May 7Oct 1Apr 24Oct 6
1976May 7Sep 23May 6Sep 23
1975May 1Sep 12Apr 20Oct 25
1974May 17Sep 21Apr 23Sep 29
1973May 16Sep 16May 14Oct 28
1972May 9Sep 21May 6Oct 6
1971May 19no dataApr 26no data
1970May 21Sep 13May 5Sep 13
1969Jun 12Oct 8May 17Oct 8
1968May 20Oct 3May 11Oct 4
1967May 13Sep 27May 12Sep 27
1966no dataSep 25no dataOct 15
1965May 28no dataMay 28no data
1964no dataSep 11no dataSep 11
1963May 22Oct 27May 22Oct 28
1962Jun 1Sep 4May 6Oct 23
1961May 17Sep 11May 9Sep 28
1960May 7Sep 30May 6Oct 15
1959May 27Sep 10May 20Sep 15
1958May 22Sep 25May 22Sep 30
1955May 8Sep 10May 8Sep 11
1954no dataSep 21no dataOct 4
1953May 15Sep 21May 14Oct 6
1952May 17no dataMay 10no data
1951May 10Sep 15Apr 24Sep 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.