Last Frost Day

Frost history / Jess Valley, CA

Jess Valley, CA: frost dates by year

Last spring and first fall frost at NOAA station USC00044374, 1951 to 2017, measured from daily minimum temperatures.

Elevation 5,400 ft, 41.268, -120.295. Download the data (JSON), NOAA daily records

Summary at 32°F

Last spring frostFirst fall frost
MedianJun 22Sep 11
EarliestMay 15 (2015)Aug 2 (1985)
LatestJul 25 (1994)Oct 21 (2012)
Trend0.8 days earlier per decadelittle change (less than half a day per decade)
Years with data5248

At 28°F (hard freeze) the median last spring date is May 26 and the median first fall date is Oct 1.

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 30May 15May 30Jun 14Jun 29Jul 14Jul 29Aug 131960197019801990200020101951: Jun 81952: Jun 301953: Jun 241955: Jul 71956: Jun 51957: Jun 161958: Jun 41959: Jun 101960: Jun 211961: Jul 61962: Jun 61963: Jun 291964: Jun 271965: Jun 271966: Jul 31967: Jun 21968: Jun 301969: Jun 291970: Jun 301971: Jun 21972: Jun 111973: Jun 181974: Jun 171975: Jul 21976: Jul 11977: May 291978: Jun 251979: Jun 171980: Jun 261981: Jun 171982: Jun 101983: Jul 201984: Jun 91985: Jun 251986: Jul 51987: Jul 171988: Jun 291989: May 311990: Jun 131991: Jun 251992: Jun 21993: Jun 231994: Jul 251996: Jun 222010: Jul 42011: Jun 92012: Jun 252013: Jun 222014: Jun 192015: May 152016: May 272017: Jun 15

First fall frost (32°F)

Jul 14Jul 29Aug 13Aug 28Sep 12Sep 27Oct 12Oct 271960197019801990200020101951: Oct 51952: Sep 101953: Sep 231954: Sep 121955: Sep 181956: Sep 211957: Sep 191958: Sep 201959: Aug 211960: Aug 231961: Sep 81962: Oct 41963: Oct 161964: Aug 291965: Sep 71966: Sep 141967: Oct 41968: Aug 221969: Sep 211970: Sep 51971: Sep 31973: Sep 11974: Sep 271975: Sep 21976: Sep 71977: Sep 151978: Aug 141979: Aug 201980: Sep 141981: Sep 211982: Sep 111983: Sep 21984: Sep 11985: Aug 21986: Sep 101987: Sep 151988: Sep 171989: Oct 31990: Oct 31991: Sep 221993: Aug 241995: Aug 192010: Sep 102011: Oct 62012: Oct 212013: Sep 182015: Sep 42016: Sep 5

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
2017Jun 15no dataMay 19no data
2016May 27Sep 5Apr 27Sep 23
2015May 15Sep 4May 14Oct 21
2014Jun 19no dataMay 30no data
2013Jun 22Sep 18May 24Sep 27
2012Jun 25Oct 21Jun 7Oct 21
2011Jun 9Oct 6Jun 4Oct 25
2010Jul 4Sep 10Jun 17Oct 12
1996Jun 22no dataMay 23no data
1995no dataAug 19no dataOct 4
1994Jul 25no dataJun 14no data
1993Jun 23Aug 24Jun 13Sep 21
1992Jun 2no dataMay 3no data
1991Jun 25Sep 22Jun 4Oct 23
1990Jun 13Oct 3Jun 1Oct 5
1989May 31Oct 3May 19Oct 3
1988Jun 29Sep 17May 14Sep 18
1987Jul 17Sep 15May 24Oct 14
1986Jul 5Sep 10May 22Sep 10
1985Jun 25Aug 2May 30Sep 8
1984Jun 9Sep 1May 16Sep 22
1983Jul 20Sep 2Jun 12Sep 9
1982Jun 10Sep 11Jun 10Sep 11
1981Jun 17Sep 21Jun 14Sep 22
1980Jun 26Sep 14May 24Sep 21
1979Jun 17Aug 20Jun 8Oct 22
1978Jun 25Aug 14Jun 25Sep 8
1977May 29Sep 15May 29Sep 21
1976Jul 1Sep 7Jun 4Oct 3
1975Jul 2Sep 2May 25Oct 8
1974Jun 17Sep 27Jun 7Oct 4
1973Jun 18Sep 1Jun 18Sep 26
1972Jun 11no dataJun 11no data
1971Jun 2Sep 3May 18Oct 1
1970Jun 30Sep 5May 12Sep 13
1969Jun 29Sep 21May 4Oct 2
1968Jun 30Aug 22May 13Sep 21
1967Jun 2Oct 4May 13Oct 6
1966Jul 3Sep 14Jun 4Oct 3
1965Jun 27Sep 7May 24Sep 17
1964Jun 27Aug 29May 7Sep 2
1963Jun 29Oct 16Jun 29Oct 24
1962Jun 6Oct 4Jun 4Oct 5
1961Jul 6Sep 8May 27Sep 21
1960Jun 21Aug 23May 23Aug 23
1959Jun 10Aug 21May 20Aug 21
1958Jun 4Sep 20May 13Sep 24
1957Jun 16Sep 19May 3Oct 7
1956Jun 5Sep 21May 14Oct 13
1955Jul 7Sep 18Jun 1Oct 6
1954no dataSep 12no dataSep 29
1953Jun 24Sep 23Jun 10Oct 2
1952Jun 30Sep 10Jun 15Oct 19
1951Jun 8Oct 5May 14Oct 5

"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.