Last Frost Day

Frost history / Winthrop 1 Wsw, WA

Winthrop 1 Wsw, WA: frost dates by year

Last spring and first fall frost at NOAA station USC00459376, 1951 to 2025, measured from daily minimum temperatures.

Elevation 1,749 ft, 48.474, -120.189. Download the data (JSON), NOAA daily records

Summary at 32°F

Last spring frostFirst fall frost
MedianMay 20Sep 19
EarliestApr 24 (2018)Aug 10 (1985)
LatestJul 8 (1981)Oct 16 (2022)
Trend1.9 days earlier per decade1.9 days later per decade
Years with data6670

At 28°F (hard freeze) the median last spring date is May 2 and the median first fall date is Oct 3.

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)

Apr 15Apr 30May 15May 30Jun 14Jun 29Jul 1419601970198019902000201020201951: May 311952: Jun 131953: May 231954: Jun 181955: May 301956: May 131957: Apr 261958: May 141959: May 131960: Jun 181961: May 111962: Jun 61963: May 141965: May 211966: May 221967: May 311969: May 181975: Jun 281976: Jun 51977: Jun 21978: May 251979: Jul 21980: May 41981: Jul 81983: May 191984: Jun 31985: May 151986: May 231987: May 191988: May 191989: May 251991: Jun 41992: May 161993: May 81994: May 31995: May 41996: May 201997: May 211998: May 161999: Jun 92000: May 132001: May 292002: Jun 72003: May 192004: May 132005: May 232006: May 132007: May 202008: May 92009: May 212010: May 252011: May 182012: Jun 72013: May 22014: May 302015: May 92016: Jun 152017: May 172018: Apr 242019: May 12020: May 82021: May 192022: May 132023: Apr 252024: Jun 162025: May 9

First fall frost (32°F)

Jul 29Aug 13Aug 28Sep 12Sep 27Oct 12Oct 2719601970198019902000201020201951: Oct 151952: Oct 41953: Sep 201954: Sep 291955: Sep 171956: Sep 41957: Sep 191958: Sep 31959: Sep 91960: Sep 21961: Sep 81962: Sep 41963: Oct 81964: Sep 11965: Aug 301966: Sep 301967: Sep 131968: Sep 191969: Aug 291970: Sep 91971: Sep 141973: Aug 191975: Sep 181976: Sep 71977: Sep 171978: Sep 111979: Sep 291980: Aug 291981: Sep 241982: Sep 101983: Sep 191984: Aug 291985: Aug 101986: Sep 121987: Sep 171988: Sep 181989: Oct 31990: Oct 51991: Sep 221992: Sep 61993: Sep 131995: Sep 211996: Sep 211997: Oct 61998: Oct 41999: Sep 272000: Sep 112001: Sep 292002: Sep 212003: Oct 92006: Sep 162007: Sep 212008: Sep 232009: Sep 282010: Sep 222011: Sep 202012: Sep 122013: Sep 272014: Sep 112015: Sep 222016: Sep 132017: Sep 162018: Sep 172019: Oct 12020: Sep 262021: Oct 12022: Oct 162023: Sep 292024: Sep 282025: Oct 3

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
2025May 9Oct 3Apr 23Oct 14
2024Jun 16Sep 28May 2Sep 30
2023Apr 25Sep 29Apr 20Oct 24
2022May 13Oct 16May 10Oct 23
2021May 19Oct 1Apr 23Oct 7
2020May 8Sep 26May 4Oct 11
2019May 1Oct 1Apr 30Oct 6
2018Apr 24Sep 17Apr 23Oct 3
2017May 17Sep 16Apr 16Oct 4
2016Jun 15Sep 13Mar 26Oct 11
2015May 9Sep 22Apr 26Sep 28
2014May 30Sep 11May 30Sep 12
2013May 2Sep 27May 1Oct 4
2012Jun 7Sep 12May 11Oct 4
2011May 18Sep 20May 1Oct 13
2010May 25Sep 22Apr 25Oct 16
2009May 21Sep 28Apr 24Oct 3
2008May 9Sep 23May 2Sep 23
2007May 20Sep 21Apr 20Sep 29
2006May 13Sep 16May 3Oct 9
2005May 23no dataApr 18no data
2004May 13no dataApr 16no data
2003May 19Oct 9May 19Oct 10
2002Jun 7Sep 21May 9Oct 1
2001May 29Sep 29May 6Oct 5
2000May 13Sep 11May 7Sep 23
1999Jun 9Sep 27May 11Sep 28
1998May 16Oct 4Apr 14Oct 10
1997May 21Oct 6May 2Oct 7
1996May 20Sep 21May 9Sep 22
1995May 4Sep 21Apr 16Oct 19
1994May 3no dataMay 1no data
1993May 8Sep 13Apr 20Oct 9
1992May 16Sep 6May 1Oct 6
1991Jun 4Sep 22Apr 30Oct 4
1990no dataOct 5no dataOct 6
1989May 25Oct 3Apr 9Oct 3
1988May 19Sep 18Apr 25Oct 17
1987May 19Sep 17Apr 20Oct 10
1986May 23Sep 12May 15Oct 2
1985May 15Aug 10May 12Sep 22
1984Jun 3Aug 29May 31Sep 7
1983May 19Sep 19May 14Sep 19
1982no dataSep 10no dataSep 15
1981Jul 8Sep 24May 8Sep 24
1980May 4Aug 29Apr 30Oct 9
1979Jul 2Sep 29May 7Oct 3
1978May 25Sep 11Apr 17Oct 2
1977Jun 2Sep 17May 5Oct 2
1976Jun 5Sep 7Jun 3Oct 15
1975Jun 28Sep 18May 19Oct 7
1973no dataAug 19no dataSep 16
1971no dataSep 14no dataSep 15
1970no dataSep 9no dataSep 13
1969May 18Aug 29May 4Sep 15
1968no dataSep 19no dataSep 19
1967May 31Sep 13May 5Oct 15
1966May 22Sep 30May 22Oct 9
1965May 21Aug 30May 18Sep 16
1964no dataSep 1no dataSep 11
1963May 14Oct 8May 9Oct 19
1962Jun 6Sep 4Jun 4Sep 8
1961May 11Sep 8Apr 23Sep 14
1960Jun 18Sep 2May 22Sep 21
1959May 13Sep 9May 12Oct 10
1958May 14Sep 3Apr 21Sep 24
1957Apr 26Sep 19Apr 9Sep 19
1956May 13Sep 4May 12Oct 3
1955May 30Sep 17May 9Sep 22
1954Jun 18Sep 29May 1Oct 2
1953May 23Sep 20May 9Sep 24
1952Jun 13Oct 4Jun 13Oct 14
1951May 31Oct 15Apr 25Oct 15

"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.