Last Frost Day

Frost history / Washburn, ND

Washburn, ND: frost dates by year

Last spring and first fall frost at NOAA station USC00329195, 1951 to 2011, measured from daily minimum temperatures.

Elevation 1,755 ft, 47.298, -101.030. Download the data (JSON), NOAA daily records

Summary at 32°F

Last spring frostFirst fall frost
MedianMay 13Sep 28
EarliestApr 19 (1978)Sep 5 (1965)
LatestJun 20 (1969)Oct 27 (1963)
Trend1.6 days earlier per decade0.7 days later per decade
Years with data4744

At 28°F (hard freeze) the median last spring date is May 7 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)

Mar 31Apr 15Apr 30May 15May 30Jun 14Jun 291960197019801990200020101951: May 101952: May 281953: May 141954: May 101955: May 81956: May 41957: May 91961: May 201963: May 221965: May 281968: May 201969: Jun 201970: May 131971: May 231972: May 91973: May 191974: May 241976: May 71978: Apr 191979: May 131980: May 141982: May 71983: May 161984: May 261985: Apr 271986: May 171987: May 221988: May 131989: May 71990: May 101991: May 71992: May 231993: May 21997: May 211998: May 21999: Apr 242000: May 132001: Apr 242002: May 242003: May 202004: May 162005: May 152007: Apr 192008: May 122009: May 172010: May 92011: May 2

First fall frost (32°F)

Aug 28Sep 12Sep 27Oct 12Oct 27Nov 111960197019801990200020101951: Sep 231952: Oct 21954: Sep 211960: Sep 271963: Oct 271965: Sep 51966: Sep 141968: Oct 31969: Oct 51970: Sep 141971: Oct 111972: Sep 211973: Sep 161974: Sep 281975: Oct 91976: Sep 91977: Oct 21978: Oct 61981: Oct 61982: Sep 151983: Sep 191984: Sep 221985: Sep 241986: Sep 61987: Oct 21988: Oct 31989: Sep 121990: Oct 61991: Sep 181992: Sep 281996: Sep 291997: Sep 201998: Oct 11999: Sep 282000: Sep 232001: Oct 42002: Sep 252003: Sep 252004: Oct 12005: Oct 62007: Sep 142008: Oct 142009: Oct 92010: 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
2011May 2no dataMay 2no data
2010May 9Oct 2May 9Oct 20
2009May 17Oct 9May 16Oct 9
2008May 12Oct 14May 4Oct 14
2007Apr 19Sep 14Apr 14Oct 13
2005May 15Oct 6May 15Oct 6
2004May 16Oct 1May 14Oct 1
2003May 20Sep 25May 20Sep 30
2002May 24Sep 25May 24Oct 2
2001Apr 24Oct 4Apr 23Oct 5
2000May 13Sep 23Apr 20Sep 24
1999Apr 24Sep 28Apr 23Oct 1
1998May 2Oct 1Apr 17Oct 1
1997May 21Sep 20May 20Oct 13
1996no dataSep 29no dataOct 18
1993May 2no dataMay 1no data
1992May 23Sep 28Apr 26Sep 28
1991May 7Sep 18May 7Sep 19
1990May 10Oct 6May 1Oct 7
1989May 7Sep 12May 6Sep 23
1988May 13Oct 3Apr 27Oct 4
1987May 22Oct 2May 22Oct 2
1986May 17Sep 6May 1Oct 12
1985Apr 27Sep 24Apr 26Sep 24
1984May 26Sep 22May 26Sep 25
1983May 16Sep 19May 16Sep 21
1982May 7Sep 15May 7Oct 13
1981no dataOct 6no dataOct 21
1980May 14no dataMay 11no data
1979May 13no dataMay 10no data
1978Apr 19Oct 6Apr 19Oct 18
1977no dataOct 2no dataOct 6
1976May 7Sep 9May 7Sep 27
1975no dataOct 9no dataOct 24
1974May 24Sep 28Apr 23Sep 28
1973May 19Sep 16May 14Oct 28
1972May 9Sep 21May 6Oct 7
1971May 23Oct 11Apr 14Oct 29
1970May 13Sep 14May 6Sep 14
1969Jun 20Oct 5May 20Oct 8
1968May 20Oct 3May 20Oct 4
1966no dataSep 14no dataOct 14
1965May 28Sep 5May 28Sep 19
1963May 22Oct 27May 22Oct 27
1961May 20no dataMay 20no data
1960no dataSep 27no dataOct 15
1957May 9no dataApr 14no data
1956May 4no dataMay 4no data
1955May 8no dataMay 8no data
1954May 10Sep 21May 7Sep 21
1953May 14no dataMay 14no data
1952May 28Oct 2May 11Oct 2
1951May 10Sep 23Apr 24Sep 28

"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.