Last Frost Day

Frost history / Wapato, WA

Wapato, WA: frost dates by year

Last spring and first fall frost at NOAA station USC00458959, 1951 to 2011, measured from daily minimum temperatures.

Elevation 841 ft, 46.435, -120.420. Download the data (JSON) · NOAA daily records

Summary at 32°F

Last spring frostFirst fall frost
MedianApr 29Oct 15
EarliestMar 26 (1994)Sep 17 (1965)
LatestMay 22 (1986)Oct 29 (1973)
Trendlittle change (less than half a day per decade)1.1 days later per decade
Years with data5557

At 28°F (hard freeze) the median last spring date is Apr 8 and the median first fall date is Oct 26.

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 16Mar 31Apr 15Apr 30May 15May 301960197019801990200020101951: Apr 211952: Apr 291953: Apr 151954: Apr 291956: Apr 81957: Apr 71958: Apr 51959: Apr 141960: May 221961: May 61962: May 41963: Apr 161964: Apr 171965: May 51966: Apr 191967: Apr 281968: May 51969: Apr 301970: May 111971: May 171972: Apr 301973: Apr 81974: May 161975: May 51976: Apr 251977: May 51978: May 41979: Apr 201980: Mar 311981: May 61982: May 51983: Apr 251984: May 71985: May 121986: May 221987: Apr 191988: May 31990: Mar 291991: Apr 261992: Apr 231993: Apr 191994: Mar 261995: Apr 151996: May 81997: Apr 121999: May 102000: Apr 292001: May 22002: May 82003: May 172004: Mar 282005: Apr 152007: Apr 202010: May 62011: May 1

First fall frost (32°F)

Sep 12Sep 27Oct 12Oct 27Nov 111960197019801990200020101951: Oct 151952: Oct 151953: Oct 21954: Sep 301955: Oct 61956: Oct 221957: Oct 211958: Oct 201959: Oct 71960: Oct 131961: Oct 181962: Oct 81963: Oct 191964: Oct 161965: Sep 171966: Oct 141967: Oct 201968: Oct 71969: Oct 131970: Sep 251971: Oct 161972: Sep 241973: Oct 291974: Oct 51975: Oct 221976: Oct 161977: Oct 271978: Oct 141979: Oct 211980: Oct 171981: Oct 31982: Oct 51983: Sep 201984: Oct 141985: Sep 291986: Oct 131987: Oct 111988: Oct 271989: Oct 31990: Oct 61991: Oct 221992: Oct 151993: Oct 201994: Oct 221995: Oct 191996: Oct 161997: Oct 201998: Oct 152000: Sep 232001: Oct 202002: Oct 112003: Oct 252004: Oct 242006: Oct 92007: Oct 212010: Oct 172011: Oct 25

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
2011May 1Oct 25Apr 22Oct 26
2010May 6Oct 17Mar 30Nov 8
2007Apr 20Oct 21Apr 3Oct 27
2006no dataOct 9no dataOct 28
2005Apr 15no dataApr 13no data
2004Mar 28Oct 24Feb 28Oct 25
2003May 17Oct 25Apr 4Oct 31
2002May 8Oct 11Apr 24Oct 24
2001May 2Oct 20Apr 14Oct 28
2000Apr 29Sep 23Mar 24Oct 22
1999May 10no dataApr 8no data
1998no dataOct 15no dataOct 19
1997Apr 12Oct 20Apr 12Oct 21
1996May 8Oct 16Mar 28Oct 17
1995Apr 15Oct 19Mar 7Oct 29
1994Mar 26Oct 22Mar 23Oct 29
1993Apr 19Oct 20Mar 25Nov 4
1992Apr 23Oct 15Mar 28Oct 15
1991Apr 26Oct 22Apr 8Oct 29
1990Mar 29Oct 6Mar 25Oct 20
1989no dataOct 3no dataOct 15
1988May 3Oct 27Apr 8Oct 27
1987Apr 19Oct 11Mar 30Oct 19
1986May 22Oct 13Apr 30Nov 8
1985May 12Sep 29Apr 25Oct 8
1984May 7Oct 14Apr 13Oct 18
1983Apr 25Sep 20Apr 12Oct 12
1982May 5Oct 5May 4Oct 18
1981May 6Oct 3Apr 13Oct 21
1980Mar 31Oct 17Mar 25Oct 22
1979Apr 20Oct 21Mar 31Nov 1
1978May 4Oct 14Mar 15Oct 22
1977May 5Oct 27Mar 27Nov 3
1976Apr 25Oct 16Mar 27Oct 17
1975May 5Oct 22May 4Oct 24
1974May 16Oct 5Mar 21Oct 6
1973Apr 8Oct 29Apr 8Nov 1
1972Apr 30Sep 24Apr 30Oct 27
1971May 17Oct 16Apr 12Oct 17
1970May 11Sep 25Apr 12Oct 27
1969Apr 30Oct 13Mar 24Oct 14
1968May 5Oct 7Apr 16Oct 31
1967Apr 28Oct 20Apr 28Nov 5
1966Apr 19Oct 14Apr 19Nov 26
1965May 5Sep 17Mar 25Nov 29
1964Apr 17Oct 16Apr 12Nov 6
1963Apr 16Oct 19Apr 16Oct 26
1962May 4Oct 8Mar 29Nov 14
1961May 6Oct 18Mar 21Oct 20
1960May 22Oct 13Apr 16Nov 4
1959Apr 14Oct 7Mar 20Nov 5
1958Apr 5Oct 20Mar 16Oct 23
1957Apr 7Oct 21Mar 26Nov 4
1956Apr 8Oct 22Apr 6Oct 22
1955no dataOct 6no dataOct 31
1954Apr 29Sep 30Apr 29Oct 2
1953Apr 15Oct 2Apr 12Nov 2
1952Apr 29Oct 15Apr 29Nov 2
1951Apr 21Oct 15Apr 21Oct 17

"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 1991–2020 frost probabilities.