Last Frost Day

Frost history / Mt Vernon 3 Wnw, WA

Mt Vernon 3 Wnw, WA: frost dates by year

Last spring and first fall frost at NOAA station USC00455678, 1956 to 2004, measured from daily minimum temperatures.

Elevation 14 ft, 48.440, -122.387. Download the data (JSON), NOAA daily records

Summary at 32°F

Last spring frostFirst fall frost
MedianApr 14Oct 16
EarliestMar 8 (1994)Sep 3 (1956)
LatestMay 15 (1964)Nov 23 (1965)
Trend4.9 days earlier per decade4.3 days later per decade
Years with data4347

At 28°F (hard freeze) the median last spring date is Mar 8 and the median first fall date is Nov 12.

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 1Mar 16Mar 31Apr 15Apr 30May 15May 30196019701980199020001956: Apr 181957: Apr 91958: Apr 261959: Apr 31960: Apr 221961: Apr 201962: Apr 161963: Apr 21964: May 151965: May 61966: Apr 191967: Apr 71968: Apr 221969: Apr 261970: Apr 171971: Apr 121972: Apr 221973: Apr 291974: Apr 131975: Apr 291976: Apr 151977: Apr 171978: Mar 311979: Mar 241980: Apr 31981: Apr 131982: Apr 251983: Apr 141984: Apr 261985: Apr 211986: Apr 241987: Mar 291988: Apr 71989: Mar 231990: Mar 271991: Apr 101993: Mar 281994: Mar 81995: Apr 161996: Mar 281997: Apr 51999: Apr 62004: Apr 1

First fall frost (32°F)

Aug 28Sep 12Sep 27Oct 12Oct 27Nov 11Nov 26Dec 11196019701980199020001956: Sep 31957: Sep 191958: Oct 271959: Oct 291960: Sep 211961: Sep 231962: Oct 161963: Oct 191964: Oct 261965: Nov 231966: Oct 131967: Nov 31968: Oct 31969: Oct 121970: Sep 131971: Oct 161972: Sep 271973: Oct 31974: Oct 51975: Nov 181976: Oct 161977: Nov 81978: Oct 251979: Oct 311980: Oct 161981: Oct 121982: Oct 181983: Sep 301984: Oct 161985: Oct 81986: Oct 121987: Oct 91988: Oct 281989: Oct 161990: Oct 111991: Oct 281992: Oct 141993: Nov 71994: Nov 31995: Oct 301996: Oct 261997: Nov 111998: Oct 301999: Nov 22001: Oct 282002: Oct 292004: 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
2004Apr 1Sep 30Feb 13Nov 4
2002no dataOct 29no dataOct 30
2001no dataOct 28no dataDec 24
1999Apr 6Nov 2Mar 7Dec 26
1998no dataOct 30no dataDec 19
1997Apr 5Nov 11Feb 9Nov 12
1996Mar 28Oct 26Mar 25Nov 19
1995Apr 16Oct 30Mar 3Oct 31
1994Mar 8Nov 3Feb 8Nov 18
1993Mar 28Nov 7Mar 13Nov 8
1992no dataOct 14no dataNov 24
1991Apr 10Oct 28Mar 27Oct 28
1990Mar 27Oct 11Mar 12Dec 7
1989Mar 23Oct 16Mar 4Dec 11
1988Apr 7Oct 28Mar 15Dec 15
1987Mar 29Oct 9Jan 17Oct 22
1986Apr 24Oct 12Feb 20Nov 9
1985Apr 21Oct 8Mar 11Nov 11
1984Apr 26Oct 16Jan 20Oct 31
1983Apr 14Sep 30Feb 5Nov 29
1982Apr 25Oct 18Mar 17Nov 10
1981Apr 13Oct 12Apr 13Dec 30
1980Apr 3Oct 16Mar 6Nov 12
1979Mar 24Oct 31Feb 3Nov 1
1978Mar 31Oct 25Mar 3Nov 11
1977Apr 17Nov 8Mar 16Nov 18
1976Apr 15Oct 16Mar 5Oct 17
1975Apr 29Nov 18Apr 1Nov 18
1974Apr 13Oct 5Mar 8Dec 23
1973Apr 29Oct 3Feb 20Oct 4
1972Apr 22Sep 27Feb 4Oct 30
1971Apr 12Oct 16Mar 21Oct 28
1970Apr 17Sep 13Mar 31Oct 30
1969Apr 26Oct 12Mar 13Oct 14
1968Apr 22Oct 3Feb 16Nov 4
1967Apr 7Nov 3Mar 13Nov 21
1966Apr 19Oct 13Mar 22Nov 8
1965May 6Nov 23Mar 24Dec 13
1964May 15Oct 26Apr 17Nov 14
1963Apr 2Oct 19Apr 2Nov 20
1962Apr 16Oct 16Mar 28Dec 12
1961Apr 20Sep 23Mar 4Nov 2
1960Apr 22Sep 21Mar 4Nov 27
1959Apr 3Oct 29Feb 12Oct 29
1958Apr 26Oct 27Mar 14Nov 15
1957Apr 9Sep 19Feb 23Nov 3
1956Apr 18Sep 3Mar 14Nov 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.