Last Frost Day

Frost history / Sugar City, ID

Sugar City, ID: frost dates by year

Last spring and first fall frost at NOAA station USC00108818, 1953 to 2025, measured from daily minimum temperatures.

Elevation 4,925 ft, 43.887, -111.737. Download the data (JSON), NOAA daily records

Summary at 32°F

Last spring frostFirst fall frost
MedianJun 9Sep 9
EarliestApr 30 (1957)Aug 15 (1974)
LatestJul 28 (2015)Oct 10 (1963)
Trend1.7 days later per decade1.6 days later per decade
Years with data3638

At 28°F (hard freeze) the median last spring date is May 14 and the median first fall date is Sep 17.

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 15Apr 30May 15May 30Jun 14Jun 29Jul 14Jul 29Aug 1319601970198019902000201020201955: Jun 41956: May 151957: Apr 301958: May 131959: Jul 81960: Jun 211961: May 141962: Jun 71963: Jun 301964: May 241965: May 271966: Jun 251967: May 311968: Jun 301969: Jun 11970: Jun 11971: Jun 301972: May 261973: Jun 191974: May 311975: Jun 102011: Jun 172012: Jun 112013: Jun 152014: May 302015: Jul 282016: May 292017: May 262018: Jun 122019: Jun 222020: Jun 92021: Jun 112022: May 242023: Jun 212024: Jun 192025: Jun 23

First fall frost (32°F)

Jul 29Aug 13Aug 28Sep 12Sep 27Oct 12Oct 2719601970198019902000201020201953: Sep 31954: Aug 271955: Sep 221957: Sep 91958: Sep 191959: Sep 21960: Aug 251961: Sep 31962: Aug 241963: Oct 101964: Aug 201965: Aug 301966: Aug 211967: Sep 131968: Aug 291969: Aug 311970: Sep 91971: Sep 151972: Sep 121973: Sep 161974: Aug 151975: Aug 292010: Sep 32011: Sep 212012: Sep 122013: Sep 192014: Sep 42015: Sep 62016: Aug 232017: Sep 172018: Sep 172019: Sep 302020: Sep 82021: Sep 172022: Sep 102023: Sep 242024: Aug 292025: 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
2025Jun 23Oct 6Apr 22Oct 6
2024Jun 19Aug 29May 21Aug 30
2023Jun 21Sep 24Apr 29Oct 26
2022May 24Sep 10May 23Oct 13
2021Jun 11Sep 17May 10Sep 29
2020Jun 9Sep 8May 8Sep 8
2019Jun 22Sep 30May 4Sep 30
2018Jun 12Sep 17Apr 21Sep 17
2017May 26Sep 17May 13Sep 23
2016May 29Aug 23May 12Sep 5
2015Jul 28Sep 6May 11Sep 6
2014May 30Sep 4May 13Sep 12
2013Jun 15Sep 19May 2Oct 1
2012Jun 11Sep 12Jun 7Sep 13
2011Jun 17Sep 21May 18Oct 12
2010no dataSep 3no dataSep 6
1975Jun 10Aug 29May 26Sep 18
1974May 31Aug 15May 19Sep 2
1973Jun 19Sep 16Jun 19Sep 17
1972May 26Sep 12May 12Sep 21
1971Jun 30Sep 15May 20Sep 15
1970Jun 1Sep 9May 15Sep 9
1969Jun 1Aug 31May 1Sep 15
1968Jun 30Aug 29May 16Sep 17
1967May 31Sep 13May 14Sep 13
1966Jun 25Aug 21Jun 5Oct 1
1965May 27Aug 30May 27Aug 31
1964May 24Aug 20May 12Aug 27
1963Jun 30Oct 10Apr 25Oct 16
1962Jun 7Aug 24Jun 7Aug 31
1961May 14Sep 3May 3Sep 3
1960Jun 21Aug 25May 25Aug 28
1959Jul 8Sep 2May 29Sep 23
1958May 13Sep 19May 1Sep 21
1957Apr 30Sep 9Apr 28Sep 15
1956May 15no dataMay 14no data
1955Jun 4Sep 22May 18Sep 22
1954no dataAug 27no dataSep 19
1953no dataSep 3no dataSep 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.