Last Frost Day

Frost history / Boise City 2 E, OK

Boise City 2 E, OK: frost dates by year

Last spring and first fall frost at NOAA station USC00340908, 1951 to 2017, measured from daily minimum temperatures.

Elevation 4,133 ft, 36.724, -102.481. Download the data (JSON), NOAA daily records

Summary at 32°F

Last spring frostFirst fall frost
MedianApr 30Oct 17
EarliestMar 23 (2012)Sep 18 (1971)
LatestMay 18 (1983)Nov 5 (2015)
Trend1.3 days earlier per decadelittle change (less than half a day per decade)
Years with data6058

At 28°F (hard freeze) the median last spring date is Apr 14 and the median first fall date is Oct 25.

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 16Mar 31Apr 15Apr 30May 15May 301960197019801990200020101951: May 11954: May 31955: Apr 141956: Apr 291959: Apr 281960: Apr 301961: May 21962: May 21963: Apr 231964: Apr 141965: May 91966: May 131967: May 141968: Apr 241969: Apr 281970: May 21971: May 131972: Apr 281973: Apr 271974: Apr 161975: Apr 301977: Apr 51978: May 41979: May 111980: Apr 251981: May 101982: Apr 241983: May 181984: May 81985: Apr 71986: Apr 141987: Apr 221988: May 21989: Apr 121990: May 41991: May 51992: Apr 31993: Apr 201994: Apr 301995: Apr 271996: Apr 301997: May 31998: Apr 211999: May 72000: May 132003: Apr 202004: Apr 132005: May 22006: Apr 262007: Apr 262008: May 112009: Apr 82010: May 22011: May 152012: Mar 232013: May 52014: May 22015: Apr 142016: Apr 182017: Apr 6

First fall frost (32°F)

Sep 12Sep 27Oct 12Oct 27Nov 111960197019801990200020101954: Oct 151959: Oct 171960: Oct 301961: Oct 231962: Oct 261963: Nov 11964: Oct 131965: Oct 11966: Oct 141967: Oct 161968: Oct 181969: Oct 121970: Oct 81971: Sep 181972: Oct 191973: Oct 271974: Oct 151975: Oct 241976: Oct 71977: Oct 111978: Oct 191979: Oct 221980: Oct 171981: Oct 251982: Oct 111983: Sep 211984: Sep 281985: Sep 291986: Oct 121987: Oct 201988: Oct 281989: Oct 171990: Oct 91991: Oct 201992: Oct 81993: Oct 91994: Oct 91995: Sep 211996: Oct 181997: Oct 251998: Oct 181999: Sep 292000: Sep 252001: Oct 132003: Oct 262004: Oct 142005: Oct 232006: Oct 192007: Oct 192008: Oct 242009: Oct 22010: Oct 262011: Oct 202012: Oct 82013: Oct 62014: Oct 312015: Nov 52016: Oct 7

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

"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.