Last Frost Day

Frost history / Glenns Ferry, ID

Glenns Ferry, ID: frost dates by year

Last spring and first fall frost at NOAA station USC00103631, 1951 to 2025, measured from daily minimum temperatures.

Elevation 2,466 ft, 42.940, -115.323. Download the data (JSON), NOAA daily records

Summary at 32°F

Last spring frostFirst fall frost
MedianMay 14Sep 30
EarliestApr 1 (2016)Sep 9 (1976)
LatestJun 26 (1976)Oct 26 (2023)
Trend3.5 days earlier per decade2.6 days later per decade
Years with data4237

At 28°F (hard freeze) the median last spring date is Apr 22 and the median first fall date is Oct 10.

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 1419601970198019902000201020201951: Jun 31952: Apr 161953: May 251954: Jun 21955: May 281956: May 11960: May 221961: May 51962: May 251963: Apr 241964: May 61965: May 181966: May 231967: May 121968: May 161969: May 31970: May 141971: May 231974: May 311975: May 261976: Jun 261977: May 281978: May 311979: May 301980: Apr 161981: May 91984: May 71985: May 131986: May 241987: May 221988: May 182007: May 42016: Apr 12017: May 142018: Apr 192019: May 32020: Apr 182021: Apr 272022: May 102023: Apr 192024: Apr 292025: Apr 21

First fall frost (32°F)

Aug 28Sep 12Sep 27Oct 12Oct 27Nov 1119601970198019902000201020201952: Sep 141959: Sep 291960: Sep 221961: Sep 221962: Oct 11963: Oct 241964: Sep 271965: Sep 171966: Oct 41967: Oct 131968: Sep 231969: Oct 41970: Sep 151971: Sep 171974: Sep 281975: Oct 181976: Sep 91977: Sep 231978: Sep 191980: Sep 221982: Oct 21983: Sep 101984: Sep 251985: Sep 201986: Sep 162014: Oct 112015: Oct 142016: Oct 22017: Oct 32018: Oct 122019: Sep 302020: Oct 232021: Oct 122022: Oct 202023: Oct 262024: Sep 302025: Oct 6

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 21Oct 6Apr 18Oct 20
2024Apr 29Sep 30Apr 18Oct 18
2023Apr 19Oct 26Apr 19Oct 28
2022May 10Oct 20Apr 13Oct 28
2021Apr 27Oct 12Apr 10Nov 8
2020Apr 18Oct 23Apr 18Oct 26
2019May 3Sep 30May 1Oct 10
2018Apr 19Oct 12Apr 19Oct 15
2017May 14Oct 3Apr 15Oct 9
2016Apr 1Oct 2Mar 26Oct 2
2015no dataOct 14no dataOct 15
2014no dataOct 11no dataNov 8
2007May 4no dataApr 21no data
1988May 18no dataMay 3no data
1987May 22no dataApr 21no data
1986May 24Sep 16May 23Sep 20
1985May 13Sep 20May 13Sep 29
1984May 7Sep 25May 7Sep 25
1983no dataSep 10no dataSep 21
1982no dataOct 2no dataOct 9
1981May 9no dataApr 14no data
1980Apr 16Sep 22Apr 16Oct 18
1979May 30no dataApr 21no data
1978May 31Sep 19Apr 22Oct 3
1977May 28Sep 23Apr 20Oct 4
1976Jun 26Sep 9May 29Oct 5
1975May 26Oct 18May 26Oct 23
1974May 31Sep 28May 16Oct 4
1971May 23Sep 17Apr 11Sep 27
1970May 14Sep 15Apr 21Oct 13
1969May 3Oct 4Apr 30Oct 5
1968May 16Sep 23May 7Oct 8
1967May 12Oct 13May 12Oct 16
1966May 23Oct 4May 23Oct 10
1965May 18Sep 17May 3Sep 18
1964May 6Sep 27May 6Oct 17
1963Apr 24Oct 24Apr 24Oct 27
1962May 25Oct 1Apr 30Oct 17
1961May 5Sep 22Apr 23Oct 2
1960May 22Sep 22Apr 25Oct 9
1959no dataSep 29no dataOct 21
1956May 1no dataApr 30no data
1955May 28no dataApr 16no data
1954Jun 2no dataMay 2no data
1953May 25no dataMay 11no data
1952Apr 16Sep 14Apr 11Oct 15
1951Jun 3no dataApr 22no data

"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.