Last Frost Day

Frost history / Bruneau, ID

Bruneau, ID: frost dates by year

Last spring and first fall frost at NOAA station USC00101195, 1962 to 2011, measured from daily minimum temperatures.

Elevation 2,530 ft, 42.882, -115.802. Download the data (JSON), NOAA daily records

Summary at 32°F

Last spring frostFirst fall frost
MedianMay 6Oct 5
EarliestMar 31 (2009)Sep 14 (1970)
LatestMay 25 (1975)Oct 30 (1979)
Trend2.3 days earlier per decade1.1 days later per decade
Years with data4045

At 28°F (hard freeze) the median last spring date is Apr 22 and the median first fall date is Oct 16.

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 30197019801990200020101963: Apr 231965: May 71966: May 231967: May 131968: May 71969: May 31971: May 201973: May 111974: May 171975: May 251976: Apr 291978: Apr 221979: Apr 251980: Apr 161981: May 71982: May 51983: May 121984: May 161985: May 131986: May 231987: Apr 211988: May 21989: May 191990: May 11991: Apr 301992: Apr 241996: May 41997: May 21999: May 162000: May 122001: May 62002: May 82003: May 202004: Apr 282005: Apr 162006: May 102007: May 42009: Mar 312010: Apr 302011: Apr 24

First fall frost (32°F)

Aug 28Sep 12Sep 27Oct 12Oct 27Nov 11197019801990200020101962: Oct 51963: Oct 201964: Sep 271965: Sep 171967: Oct 61968: Sep 231969: Oct 51970: Sep 141971: Sep 181972: Sep 241973: Oct 31974: Sep 281975: Oct 231976: Oct 181977: Oct 41978: Oct 31979: Oct 301980: Oct 171981: Oct 11982: Oct 101983: Sep 211984: Sep 241985: Sep 301986: Oct 111987: Oct 101988: Oct 281989: Oct 51990: Oct 71991: Oct 181993: Oct 91995: Sep 221996: Sep 231997: Oct 81998: Oct 171999: Sep 282000: Sep 242001: Oct 102002: Sep 222003: Oct 132004: Sep 202005: Sep 252006: Sep 172008: Oct 112009: Oct 292011: Oct 26

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
2011Apr 24Oct 26Feb 28Nov 2
2010Apr 30no dataApr 10no data
2009Mar 31Oct 29Mar 31Nov 15
2008no dataOct 11no dataNov 24
2007May 4no dataMay 3no data
2006May 10Sep 17Apr 19Oct 21
2005Apr 16Sep 25Apr 14Oct 30
2004Apr 28Sep 20Mar 29Nov 1
2003May 20Oct 13Apr 7Oct 30
2002May 8Sep 22May 8Oct 12
2001May 6Oct 10Apr 15Oct 10
2000May 12Sep 24Apr 8Oct 23
1999May 16Sep 28May 11Sep 28
1998no dataOct 17no dataOct 17
1997May 2Oct 8May 2Oct 13
1996May 4Sep 23Apr 28Oct 17
1995no dataSep 22no dataSep 22
1993no dataOct 9no dataOct 20
1992Apr 24no dataApr 7no data
1991Apr 30Oct 18Apr 26Oct 28
1990May 1Oct 7Mar 30Oct 8
1989May 19Oct 5Apr 26Oct 16
1988May 2Oct 28Apr 10Nov 7
1987Apr 21Oct 10Apr 20Oct 16
1986May 23Oct 11Apr 30Oct 12
1985May 13Sep 30Apr 24Sep 30
1984May 16Sep 24Apr 28Oct 15
1983May 12Sep 21Apr 27Sep 21
1982May 5Oct 10May 5Oct 19
1981May 7Oct 1Apr 14Oct 4
1980Apr 16Oct 17Apr 11Oct 22
1979Apr 25Oct 30Apr 19Oct 30
1978Apr 22Oct 3Apr 22Oct 22
1977no dataOct 4no dataOct 11
1976Apr 29Oct 18Apr 19Oct 18
1975May 25Oct 23May 25Oct 23
1974May 17Sep 28May 16Oct 6
1973May 11Oct 3Apr 8Oct 4
1972no dataSep 24no dataOct 27
1971May 20Sep 18Apr 12Oct 15
1970no dataSep 14no dataSep 25
1969May 3Oct 5May 3Oct 5
1968May 7Sep 23May 7Oct 8
1967May 13Oct 6May 12Oct 15
1966May 23no dataApr 27no data
1965May 7Sep 17May 6Sep 17
1964no dataSep 27no dataOct 17
1963Apr 23Oct 20Apr 21Oct 27
1962no dataOct 5no dataOct 16

"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.