Last Frost Day

Frost history / Oral, SD

Oral, SD: frost dates by year

Last spring and first fall frost at NOAA station USC00396304, 1972 to 2025, measured from daily minimum temperatures.

Elevation 2,960 ft, 43.403, -103.268. Download the data (JSON), NOAA daily records

Summary at 32°F

Last spring frostFirst fall frost
MedianMay 13Sep 21
EarliestApr 22 (2006)Aug 28 (1988)
LatestMay 31 (1974)Oct 15 (2015)
Trendlittle change (less than half a day per decade)2.4 days later per decade
Years with data4743

At 28°F (hard freeze) the median last spring date is May 6 and the median first fall date is Oct 4.

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 14198019902000201020201972: May 41973: May 221974: May 311975: May 301976: May 171977: Apr 251978: May 71979: May 111980: May 81981: May 141982: May 61983: May 201984: May 81985: May 61986: May 171987: Apr 241988: May 31989: May 261990: May 131991: May 71992: May 271993: May 201994: May 31995: Apr 271996: May 131997: May 192004: May 142005: May 282006: Apr 222007: Apr 262008: May 142009: May 172011: May 162012: May 122013: May 122014: May 152015: May 212016: May 182017: May 242018: May 22019: May 232020: May 102021: May 132022: May 252023: May 32024: May 52025: May 17

First fall frost (32°F)

Aug 13Aug 28Sep 12Sep 27Oct 12Oct 27198019902000201020201972: Sep 211973: Sep 151975: Sep 121976: Sep 281977: Oct 91978: Sep 211979: Sep 141980: Sep 261981: Sep 171982: Sep 201983: Sep 201984: Sep 241985: Sep 201986: Sep 301987: Sep 121988: Aug 281989: Sep 111990: Sep 241991: Sep 181992: Sep 81993: Sep 141994: Oct 91995: Sep 211996: Sep 242004: Oct 22006: Sep 192007: Sep 142008: Sep 242009: Sep 282010: Oct 132011: Sep 222012: Oct 42013: Sep 202014: Sep 122015: Oct 152016: Oct 62017: Sep 52018: Oct 42019: Oct 32020: Sep 92021: Oct 112022: Oct 92023: 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
2025May 17no dataApr 22no data
2024May 5no dataMay 4no data
2023May 3Oct 6May 2Oct 7
2022May 25Oct 9May 22Oct 17
2021May 13Oct 11May 12Oct 18
2020May 10Sep 9May 10Sep 10
2019May 23Oct 3May 10Oct 3
2018May 2Oct 4Apr 28Oct 6
2017May 24Sep 5May 4Oct 4
2016May 18Oct 6May 15Oct 7
2015May 21Oct 15May 21Oct 16
2014May 15Sep 12May 15Sep 13
2013May 12Sep 20May 6Oct 16
2012May 12Oct 4May 12Oct 4
2011May 16Sep 22May 3Oct 15
2010no dataOct 13no dataOct 13
2009May 17Sep 28May 16Oct 3
2008May 14Sep 24May 11Oct 7
2007Apr 26Sep 14Apr 15Sep 14
2006Apr 22Sep 19Apr 9Sep 19
2005May 28no dataMay 4no data
2004May 14Oct 2May 14Oct 2
1997May 19no dataMay 9no data
1996May 13Sep 24Apr 29Oct 15
1995Apr 27Sep 21Apr 27Sep 22
1994May 3Oct 9May 1Oct 23
1993May 20Sep 14Apr 22Sep 14
1992May 27Sep 8May 26Sep 28
1991May 7Sep 18May 6Sep 18
1990May 13Sep 24May 10Oct 9
1989May 26Sep 11May 6Oct 17
1988May 3Aug 28Apr 28Sep 23
1987Apr 24Sep 12Apr 22Oct 6
1986May 17Sep 30Apr 16Oct 12
1985May 6Sep 20May 6Sep 28
1984May 8Sep 24May 1Sep 25
1983May 20Sep 20May 19Sep 20
1982May 6Sep 20May 6Oct 7
1981May 14Sep 17May 10Oct 21
1980May 8Sep 26May 8Oct 11
1979May 11Sep 14May 11Oct 4
1978May 7Sep 21Apr 25Oct 6
1977Apr 25Oct 9Apr 25Oct 11
1976May 17Sep 28May 17Sep 28
1975May 30Sep 12Apr 20Sep 12
1974May 31no dataMay 12no data
1973May 22Sep 15May 12Sep 17
1972May 4Sep 21Apr 24Sep 21

"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.