Last Frost Day

Frost history / Whitman Mission, WA

Whitman Mission, WA: frost dates by year

Last spring and first fall frost at NOAA station USC00459200, 1963 to 2024, measured from daily minimum temperatures.

Elevation 632 ft, 46.044, -118.463. Download the data (JSON), NOAA daily records

Summary at 32°F

Last spring frostFirst fall frost
MedianMay 9Sep 24
EarliestApr 10 (1989)Aug 20 (2001)
LatestJun 1 (1984)Oct 19 (1963)
Trend2.2 days earlier per decade2.1 days later per decade
Years with data5350

At 28°F (hard freeze) the median last spring date is Apr 16 and the median first fall date is Oct 9.

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 141970198019902000201020201963: Apr 161964: May 251965: May 181966: May 181967: May 261968: May 81969: May 31970: May 131971: May 201972: Apr 301973: May 211974: May 171975: May 211976: May 191977: May 61978: May 231979: May 301980: Apr 161981: May 131982: May 51983: May 131984: Jun 11985: May 131986: May 161987: May 211988: Apr 261989: Apr 101990: May 91991: May 21992: May 121993: Apr 201994: May 11995: May 141996: May 91997: May 21999: May 112000: May 72001: May 62002: May 82003: May 192004: Apr 252005: Apr 282006: May 132007: Apr 202008: May 92009: May 212010: May 92011: May 42012: May 122021: Apr 222022: May 112023: Apr 242024: May 3

First fall frost (32°F)

Aug 13Aug 28Sep 12Sep 27Oct 12Oct 271970198019902000201020201963: Oct 191964: Sep 111965: Sep 171966: Oct 31967: Oct 151968: Oct 21969: Sep 141970: Sep 131971: Sep 141972: Sep 251973: Sep 161974: Sep 131975: Sep 181976: Sep 81977: Oct 21978: Sep 191979: Oct 31980: Oct 91981: Sep 241982: Sep 141983: Sep 191984: Sep 141986: Oct 111987: Sep 171988: Sep 121989: Sep 121990: Oct 61991: Sep 221993: Sep 221994: Oct 41996: Sep 231997: Oct 81998: Oct 112000: Sep 232001: Aug 202002: Sep 212003: Oct 152004: Oct 52005: Sep 242006: Oct 102007: Oct 142008: Sep 282009: Oct 62010: Oct 122011: Oct 182012: Sep 122021: Oct 72022: Oct 162023: Sep 232024: Sep 30

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
2024May 3Sep 30Apr 24Oct 4
2023Apr 24Sep 23Apr 20Oct 28
2022May 11Oct 16Apr 18Nov 7
2021Apr 22Oct 7Apr 22Oct 11
2012May 12Sep 12May 11Oct 3
2011May 4Oct 18Apr 24Oct 25
2010May 9Oct 12May 7Oct 17
2009May 21Oct 6Apr 24Oct 10
2008May 9Sep 28May 2Oct 9
2007Apr 20Oct 14Apr 20Oct 26
2006May 13Oct 10May 3Oct 10
2005Apr 28Sep 24Apr 15Nov 8
2004Apr 25Oct 5Apr 3Oct 25
2003May 19Oct 15Apr 4Oct 25
2002May 8Sep 21Apr 4Oct 2
2001May 6Aug 20Apr 15Oct 5
2000May 7Sep 23Mar 31Sep 23
1999May 11no dataApr 16no data
1998no dataOct 11no dataOct 19
1997May 2Oct 8Apr 13Oct 21
1996May 9Sep 23Mar 26Sep 23
1995May 14no dataApr 17no data
1994May 1Oct 4Mar 27Oct 12
1993Apr 20Sep 22Mar 13Sep 22
1992May 12no dataApr 24no data
1991May 2Sep 22Apr 12Oct 4
1990May 9Oct 6Mar 27Oct 7
1989Apr 10Sep 12Mar 30Oct 3
1988Apr 26Sep 12Apr 10Oct 27
1987May 21Sep 17Apr 20Oct 9
1986May 16Oct 11Apr 30Oct 12
1985May 13no dataMar 26no data
1984Jun 1Sep 14Apr 27Sep 28
1983May 13Sep 19Apr 16Sep 20
1982May 5Sep 14May 5Sep 15
1981May 13Sep 24Apr 14Oct 5
1980Apr 16Oct 9Apr 2Oct 9
1979May 30Oct 3Apr 1Nov 1
1978May 23Sep 19Apr 13Oct 5
1977May 6Oct 2Apr 20Oct 4
1976May 19Sep 8Apr 21Oct 15
1975May 21Sep 18Apr 30Oct 24
1974May 17Sep 13Apr 14Oct 5
1973May 21Sep 16May 11Oct 3
1972Apr 30Sep 25Apr 30Sep 25
1971May 20Sep 14Apr 15Sep 17
1970May 13Sep 13Apr 26Sep 15
1969May 3Sep 14Mar 25Oct 10
1968May 8Oct 2Apr 22Oct 3
1967May 26Oct 15Apr 15Oct 20
1966May 18Oct 3Apr 19Oct 9
1965May 18Sep 17Apr 7Sep 17
1964May 25Sep 11Apr 19Oct 4
1963Apr 16Oct 19Apr 3Oct 19

"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.