Last Frost Day

Frost history / Richland, OR

Richland, OR: frost dates by year

Last spring and first fall frost at NOAA station USC00357160, 1951 to 2011, measured from daily minimum temperatures.

Elevation 2,215 ft, 44.766, -117.160. Download the data (JSON), NOAA daily records

Summary at 32°F

Last spring frostFirst fall frost
MedianMay 18Sep 29
EarliestApr 19 (2005)Sep 3 (1956)
LatestJul 15 (1983)Oct 20 (1963)
Trend2.4 days earlier per decade1.4 days later per decade
Years with data4245

At 28°F (hard freeze) the median last spring date is May 4 and the median first fall date is Oct 14.

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 291960197019801990200020101952: Jun 131955: May 311959: May 181960: May 281961: May 131962: Jun 41963: Apr 221964: May 231965: May 31966: May 231967: May 271968: May 71969: May 281970: May 141971: May 161972: Apr 301973: Jun 181974: May 211975: May 251976: Jun 261978: May 111979: May 291980: Apr 301983: Jul 151987: May 201988: May 71989: May 251990: May 171991: May 111992: May 131993: Apr 281994: May 11995: May 141996: Jun 191998: Apr 262004: May 132005: Apr 192007: May 62008: May 132009: May 212010: May 232011: May 18

First fall frost (32°F)

Aug 28Sep 12Sep 27Oct 12Oct 271960197019801990200020101951: Oct 31952: Sep 141953: Sep 201954: Sep 291955: Sep 231956: Sep 31959: Sep 291960: Sep 171961: Sep 211962: Sep 301963: Oct 201964: Sep 181965: Sep 171966: Oct 31967: Oct 41968: Sep 221969: Oct 31970: Sep 121971: Sep 121972: Sep 201973: Oct 21974: Sep 281975: Oct 81976: Oct 51977: Oct 11978: Sep 161979: Oct 41986: Oct 21987: Sep 161988: Sep 181989: Oct 151990: Oct 51991: Sep 221992: Sep 71994: Oct 41995: Sep 221996: Sep 232003: Sep 132004: Oct 102005: Sep 292006: Oct 82007: Sep 242008: Oct 92009: Oct 12010: Oct 12

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 18no dataMay 4no data
2010May 23Oct 12May 7Oct 19
2009May 21Oct 1May 13Oct 1
2008May 13Oct 9May 2Oct 9
2007May 6Sep 24May 4Oct 18
2006no dataOct 8no dataOct 15
2005Apr 19Sep 29Apr 17Nov 9
2004May 13Oct 10Apr 29Oct 25
2003no dataSep 13no dataNov 1
1998Apr 26no dataApr 18no data
1996Jun 19Sep 23May 4Sep 23
1995May 14Sep 22Apr 22Oct 5
1994May 1Oct 4Apr 15Oct 4
1993Apr 28no dataApr 20no data
1992May 13Sep 7Apr 24Oct 15
1991May 11Sep 22May 1Oct 18
1990May 17Oct 5May 8Oct 7
1989May 25Oct 15Apr 11Oct 16
1988May 7Sep 18May 3Oct 27
1987May 20Sep 16Apr 20Oct 11
1986no dataOct 2no dataOct 10
1983Jul 15no dataJul 14no data
1980Apr 30no dataApr 13no data
1979May 29Oct 4May 29Oct 29
1978May 11Sep 16May 5Oct 12
1977no dataOct 1no dataOct 11
1976Jun 26Oct 5Apr 26Oct 18
1975May 25Oct 8May 25Oct 24
1974May 21Sep 28May 20Oct 5
1973Jun 18Oct 2May 21Oct 2
1972Apr 30Sep 20Apr 30Sep 26
1971May 16Sep 12May 16Sep 17
1970May 14Sep 12May 13Sep 14
1969May 28Oct 3May 28Oct 4
1968May 7Sep 22Apr 27Oct 8
1967May 27Oct 4May 2Oct 15
1966May 23Oct 3May 23Oct 17
1965May 3Sep 17May 3Sep 17
1964May 23Sep 18May 23Oct 17
1963Apr 22Oct 20Apr 22Oct 26
1962Jun 4Sep 30Jun 4Oct 16
1961May 13Sep 21Apr 21Sep 21
1960May 28Sep 17May 21Oct 25
1959May 18Sep 29May 4Oct 25
1956no dataSep 3no dataOct 14
1955May 31Sep 23May 29Sep 27
1954no dataSep 29no dataSep 29
1953no dataSep 20no dataSep 23
1952Jun 13Sep 14Apr 29Oct 16
1951no dataOct 3no dataOct 24

"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.