Last Frost Day

Frost history / St John, WA

St John, WA: frost dates by year

Last spring and first fall frost at NOAA station USC00457267, 1963 to 2019, measured from daily minimum temperatures.

Elevation 1,952 ft, 47.093, -117.588. Download the data (JSON), NOAA daily records

Summary at 32°F

Last spring frostFirst fall frost
MedianMay 20Sep 21
EarliestApr 6 (1993)Aug 22 (1985)
LatestJul 13 (1979)Oct 25 (2011)
Trend7.6 days earlier per decade3.9 days later per decade
Years with data5553

At 28°F (hard freeze) the median last spring date is May 1 and the median first fall date is Oct 6.

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 29Jul 14Jul 29197019801990200020101964: Jun 281965: May 181966: May 231967: May 311968: Jun 281969: May 41970: May 181971: Jul 71972: May 251973: May 221974: May 171975: May 211976: Jun 51977: May 301978: May 301979: Jul 131980: Jun 41981: Jul 121982: Jun 101983: Jun 211984: Jul 71985: Jun 251986: May 171987: May 201988: May 41989: May 201990: May 81991: Jun 41992: May 221993: Apr 61994: May 11995: Apr 301996: May 101997: May 221998: Apr 261999: May 162000: May 72001: May 202002: Jun 72003: Apr 202004: Apr 292005: Apr 302006: May 132007: Apr 302008: May 92009: May 212010: May 242011: May 42012: May 122013: May 242014: May 122015: May 62017: Apr 152018: Apr 222019: Apr 29

First fall frost (32°F)

Aug 13Aug 28Sep 12Sep 27Oct 12Oct 27Nov 11197019801990200020101963: Sep 181964: Sep 91965: Aug 301966: Aug 311967: Sep 231968: Oct 21969: Sep 61971: Sep 141972: Sep 251973: Oct 11974: Sep 111975: Sep 261976: Sep 71977: Sep 221978: Sep 161980: Aug 251982: Sep 131983: Sep 191984: Sep 141985: Aug 221986: Oct 21987: Sep 171988: Sep 181989: Sep 101990: Sep 201991: Sep 141992: Aug 231993: Sep 211994: Oct 81995: Sep 221996: Sep 231997: Oct 61998: Oct 151999: Sep 272000: Sep 232001: Oct 62002: Sep 212003: Oct 112004: Oct 242005: Sep 212006: Sep 152007: Sep 202008: Sep 232009: Sep 212010: Sep 122011: Oct 252012: Sep 112013: Oct 32014: Oct 32015: Sep 272016: Sep 142017: Oct 132018: Oct 14

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
2019Apr 29no dataMar 15no data
2018Apr 22Oct 14Apr 2Nov 8
2017Apr 15Oct 13Apr 3Nov 3
2016no dataSep 14no dataOct 12
2015May 6Sep 27Apr 26Sep 27
2014May 12Oct 3Apr 19Nov 11
2013May 24Oct 3May 2Oct 13
2012May 12Sep 11May 11Oct 6
2011May 4Oct 25Apr 19Oct 26
2010May 24Sep 12May 5Oct 17
2009May 21Sep 21Apr 24Oct 5
2008May 9Sep 23May 2Oct 8
2007Apr 30Sep 20Apr 20Oct 25
2006May 13Sep 15May 13Sep 15
2005Apr 30Sep 21Apr 13Nov 8
2004Apr 29Oct 24Apr 1Oct 28
2003Apr 20Oct 11Apr 20Oct 24
2002Jun 7Sep 21May 10Sep 30
2001May 20Oct 6May 6Oct 7
2000May 7Sep 23May 7Sep 23
1999May 16Sep 27May 11Sep 28
1998Apr 26Oct 15Apr 19Oct 16
1997May 22Oct 6Apr 12Oct 8
1996May 10Sep 23May 10Sep 23
1995Apr 30Sep 22Apr 17Oct 28
1994May 1Oct 8Mar 27Oct 12
1993Apr 6Sep 21Mar 16Sep 22
1992May 22Aug 23May 12Oct 7
1991Jun 4Sep 14Apr 10Sep 22
1990May 8Sep 20Apr 4Oct 6
1989May 20Sep 10Mar 4Oct 15
1988May 4Sep 18Apr 25Sep 18
1987May 20Sep 17May 20Oct 11
1986May 17Oct 2May 14Oct 12
1985Jun 25Aug 22May 16Aug 22
1984Jul 7Sep 14Jun 1Sep 28
1983Jun 21Sep 19May 14Sep 19
1982Jun 10Sep 13Jun 8Oct 1
1981Jul 12no dataJul 11no data
1980Jun 4Aug 25Apr 7Aug 26
1979Jul 13no dataJun 14no data
1978May 30Sep 16May 30Sep 18
1977May 30Sep 22May 6Oct 3
1976Jun 5Sep 7Apr 16Sep 8
1975May 21Sep 26Apr 29Oct 23
1974May 17Sep 11May 16Sep 13
1973May 22Oct 1Apr 29Oct 4
1972May 25Sep 25May 1Sep 25
1971Jul 7Sep 14Apr 19Sep 15
1970May 18no dataApr 28no data
1969May 4Sep 6Apr 14Sep 15
1968Jun 28Oct 2May 3Oct 16
1967May 31Sep 23May 4Oct 15
1966May 23Aug 31May 18Oct 3
1965May 18Aug 30May 18Sep 17
1964Jun 28Sep 9May 25Oct 3
1963no dataSep 18no dataOct 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.