Last Frost Day

Frost history / Bonners Ferry, ID

Bonners Ferry, ID: frost dates by year

Last spring and first fall frost at NOAA station USC00101079, 1951 to 2025, measured from daily minimum temperatures.

Elevation 2,075 ft, 48.693, -116.310. Download the data (JSON), NOAA daily records

Summary at 32°F

Last spring frostFirst fall frost
MedianMay 12Sep 25
EarliestMar 31 (2016)Aug 29 (1980)
LatestJul 31 (1993)Nov 6 (2022)
Trend2.4 days earlier per decade4.4 days later per decade
Years with data6664

At 28°F (hard freeze) the median last spring date is Apr 22 and the median first fall date is Oct 9.

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 30Jun 14Jun 29Jul 14Jul 29Aug 1319601970198019902000201020201951: May 311952: May 71954: May 141955: May 231956: May 131957: Apr 261958: Apr 301959: May 131960: May 231961: Apr 261962: May 51963: May 111964: May 261965: May 181966: May 231967: May 261968: May 111969: May 51970: May 121971: Apr 301972: May 31973: May 211974: May 101975: May 251976: May 191977: May 301978: May 231979: May 171980: Jun 41981: May 51982: May 111983: May 141984: May 221985: May 131986: May 231987: May 221988: May 21989: May 201991: May 41992: May 121993: Jul 311994: May 21995: May 41996: May 91997: Apr 221998: May 161999: Jun 102000: May 132001: May 202002: May 152005: May 22011: May 12012: May 122013: May 12014: Apr 192015: Apr 232016: Mar 312017: Apr 172018: Apr 222019: Apr 302020: May 42021: May 192022: Apr 302023: Apr 242024: May 12025: Apr 24

First fall frost (32°F)

Aug 13Aug 28Sep 12Sep 27Oct 12Oct 27Nov 1119601970198019902000201020201951: Sep 261954: Sep 291955: Sep 221956: Sep 51958: Sep 271959: Sep 91960: Sep 101961: Sep 121962: Sep 31963: Oct 81964: Sep 111965: Sep 61966: Oct 31967: Sep 231968: Oct 21969: Sep 151970: Sep 121971: Sep 141972: Sep 111973: Sep 151974: Sep 131975: Oct 161976: Sep 81977: Oct 31978: Sep 171979: Sep 291980: Aug 291981: Sep 231982: Sep 141983: Sep 191984: Sep 141985: Sep 221986: Sep 121987: Sep 171988: Oct 171990: Oct 61991: Sep 21992: Sep 71994: Oct 41995: Sep 211996: Sep 231997: Oct 81998: Oct 191999: Sep 262000: Sep 222001: Oct 42002: Sep 222004: Oct 242005: Sep 242007: Oct 142011: Oct 162012: Oct 42013: Oct 42014: Oct 32015: Oct 232016: Oct 112017: Oct 42018: Oct 52019: Oct 12020: Oct 162021: Oct 82022: Nov 62023: Oct 252025: Oct 15

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
2025Apr 24Oct 15Apr 22Nov 29
2024May 1no dataMar 28no data
2023Apr 24Oct 25Apr 16Oct 27
2022Apr 30Nov 6Apr 21Nov 6
2021May 19Oct 8Apr 13Oct 11
2020May 4Oct 16Apr 16Oct 23
2019Apr 30Oct 1Apr 29Oct 1
2018Apr 22Oct 5Apr 9Oct 14
2017Apr 17Oct 4Apr 16Oct 30
2016Mar 31Oct 11Mar 20Oct 12
2015Apr 23Oct 23Apr 16Oct 24
2014Apr 19Oct 3Apr 2Nov 10
2013May 1Oct 4May 1Oct 15
2012May 12Oct 4Apr 8Oct 5
2011May 1Oct 16Apr 13Oct 25
2007no dataOct 14no dataOct 26
2005May 2Sep 24Apr 30Nov 8
2004no dataOct 24no dataOct 26
2002May 15Sep 22May 9Oct 2
2001May 20Oct 4Apr 16Oct 4
2000May 13Sep 22Apr 14Sep 22
1999Jun 10Sep 26May 9Sep 27
1998May 16Oct 19Apr 14Oct 19
1997Apr 22Oct 8Apr 12Oct 20
1996May 9Sep 23Apr 20Oct 17
1995May 4Sep 21Apr 20Sep 21
1994May 2Oct 4Mar 31Oct 13
1993Jul 31no dataMar 16no data
1992May 12Sep 7Apr 8Sep 29
1991May 4Sep 2Apr 16Sep 2
1990no dataOct 6no dataOct 6
1989May 20no dataApr 12no data
1988May 2Oct 17Apr 27Oct 18
1987May 22Sep 17Apr 20Oct 10
1986May 23Sep 12Apr 30Oct 11
1985May 13Sep 22May 13Sep 23
1984May 22Sep 14Apr 30Sep 24
1983May 14Sep 19May 13Sep 19
1982May 11Sep 14May 9Sep 15
1981May 5Sep 23Apr 18Oct 5
1980Jun 4Aug 29Apr 13Oct 10
1979May 17Sep 29Apr 15Oct 3
1978May 23Sep 17Apr 24Oct 6
1977May 30Oct 3Apr 19Oct 3
1976May 19Sep 8Apr 5Oct 4
1975May 25Oct 16Apr 22Oct 23
1974May 10Sep 13May 10Sep 30
1973May 21Sep 15May 11Sep 16
1972May 3Sep 11May 1Sep 27
1971Apr 30Sep 14Apr 14Sep 17
1970May 12Sep 12May 12Sep 12
1969May 5Sep 15Apr 26Oct 12
1968May 11Oct 2Apr 22Oct 2
1967May 26Sep 23Apr 30Oct 20
1966May 23Oct 3May 18Oct 9
1965May 18Sep 6May 8Sep 16
1964May 26Sep 11May 25Oct 4
1963May 11Oct 8May 4Oct 19
1962May 5Sep 3May 5Nov 7
1961Apr 26Sep 12Apr 26Sep 27
1960May 23Sep 10May 23Oct 10
1959May 13Sep 9May 12Oct 10
1958Apr 30Sep 27Apr 29Sep 30
1957Apr 26no dataApr 9no data
1956May 13Sep 5Apr 12Oct 22
1955May 23Sep 22May 13Sep 24
1954May 14Sep 29May 2Sep 29
1952May 7no dataApr 21no data
1951May 31Sep 26Apr 25Oct 25

"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.