Last Frost Day

Frost history / Twin Falls 6 E, ID

Twin Falls 6 E, ID: frost dates by year

Last spring and first fall frost at NOAA station USC00109303, 1963 to 2012, measured from daily minimum temperatures.

Elevation 3,960 ft, 42.546, -114.346. Download the data (JSON), NOAA daily records

Summary at 32°F

Last spring frostFirst fall frost
MedianMay 10Sep 29
EarliestApr 15 (1994)Aug 25 (1992)
LatestJun 7 (1995)Oct 23 (1975)
Trend0.6 days later per decadelittle change (less than half a day per decade)
Years with data4543

At 28°F (hard freeze) the median last spring date is Apr 30 and the median first fall date is Oct 11.

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 14197019801990200020101964: May 61965: May 101966: May 231967: May 121968: May 81969: May 31970: May 141971: May 211972: May 91973: May 111974: May 161975: May 251976: Apr 271977: May 281978: May 311979: Apr 261980: Apr 161981: May 91982: May 61983: May 141984: May 81985: May 151986: May 231988: May 71989: May 191990: May 251991: May 51992: Apr 241993: May 91994: Apr 151995: Jun 71996: May 41997: May 81998: Apr 262000: May 122001: May 42003: May 202004: May 132006: May 102007: May 232008: May 102009: May 132010: May 252011: Jun 32012: May 7

First fall frost (32°F)

Aug 13Aug 28Sep 12Sep 27Oct 12Oct 27Nov 11197019801990200020101963: Oct 171964: Sep 271965: Sep 161966: Oct 41967: Oct 131968: Oct 31969: Oct 41970: Sep 141971: Sep 191972: Sep 121973: Oct 31974: Oct 51975: Oct 231976: Sep 81977: Oct 21978: Sep 181979: Oct 41980: Sep 221981: Sep 231982: Oct 61983: Sep 101984: Sep 221986: Sep 211987: Sep 171988: Sep 121989: Oct 51990: Oct 71991: Sep 221992: Aug 251993: Sep 131994: Oct 151995: Sep 222001: Oct 42002: Oct 12003: Sep 142004: Oct 62005: Oct 52006: Sep 172007: Sep 292008: Sep 22009: Oct 12010: Oct 122011: Oct 18

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
2012May 7no dataApr 8no data
2011Jun 3Oct 18Apr 30Oct 18
2010May 25Oct 12May 23Oct 20
2009May 13Oct 1Apr 30Oct 2
2008May 10Sep 2May 2Oct 10
2007May 23Sep 29Apr 20Sep 30
2006May 10Sep 17May 3Oct 21
2005no dataOct 5no dataOct 5
2004May 13Oct 6Mar 29Nov 1
2003May 20Sep 14May 19Oct 11
2002no dataOct 1no dataOct 12
2001May 4Oct 4May 3Oct 10
2000May 12no dataApr 30no data
1998Apr 26no dataApr 26no data
1997May 8no dataMay 2no data
1996May 4no dataApr 28no data
1995Jun 7Sep 22Jun 7Sep 22
1994Apr 15Oct 15Apr 9Oct 23
1993May 9Sep 13Apr 20Oct 26
1992Apr 24Aug 25Apr 24Oct 17
1991May 5Sep 22May 1Oct 5
1990May 25Oct 7Apr 30Oct 7
1989May 19Oct 5Apr 26Oct 16
1988May 7Sep 12May 2Nov 7
1987no dataSep 17no dataOct 11
1986May 23Sep 21May 12Oct 11
1985May 15no dataApr 26no data
1984May 8Sep 22May 7Sep 25
1983May 14Sep 10May 10Sep 21
1982May 6Oct 6May 6Oct 9
1981May 9Sep 23Apr 14Oct 4
1980Apr 16Sep 22Apr 12Oct 22
1979Apr 26Oct 4Apr 21Oct 30
1978May 31Sep 18Apr 18Oct 22
1977May 28Oct 2Apr 20Oct 11
1976Apr 27Sep 8Apr 27Oct 19
1975May 25Oct 23May 25Oct 23
1974May 16Oct 5Apr 15Oct 6
1973May 11Oct 3May 11Oct 3
1972May 9Sep 12May 1Oct 25
1971May 21Sep 19Apr 13Sep 19
1970May 14Sep 14May 11Sep 25
1969May 3Oct 4Apr 30Oct 4
1968May 8Oct 3May 7Oct 8
1967May 12Oct 13May 1Oct 15
1966May 23Oct 4May 23Oct 10
1965May 10Sep 16May 6Sep 18
1964May 6Sep 27May 6Oct 4
1963no dataOct 17no dataOct 27

"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.