Last Frost Day

Frost history / Oahe Dam, SD

Oahe Dam, SD: frost dates by year

Last spring and first fall frost at NOAA station USC00396170, 1960 to 2025, measured from daily minimum temperatures.

Elevation 1,663 ft, 44.442, -100.417. Download the data (JSON), NOAA daily records

Summary at 32°F

Last spring frostFirst fall frost
MedianMay 2Oct 10
EarliestApr 7 (1977)Sep 19 (1988)
LatestMay 28 (1965)Oct 28 (1971)
Trend0.9 days earlier per decade0.6 days later per decade
Years with data3436

At 28°F (hard freeze) the median last spring date is Apr 20 and the median first fall date is Oct 15.

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 1419601970198019902000201020201961: May 11962: May 11963: May 221964: Apr 181965: May 281966: May 131967: May 71968: Apr 251969: Apr 291970: Apr 241971: May 31972: May 81973: May 31974: May 161975: Apr 211976: May 71977: Apr 71978: Apr 261979: May 131980: May 81981: May 101982: Apr 301983: May 141984: May 91985: Apr 261986: Apr 201987: Apr 211988: Apr 271989: May 51990: Apr 302022: Apr 282023: May 22024: May 32025: Apr 29

First fall frost (32°F)

Sep 12Sep 27Oct 12Oct 27Nov 1119601970198019902000201020201960: Sep 301961: Sep 301962: Oct 251963: Oct 281964: Sep 271965: Sep 241966: Oct 151967: Sep 281968: Oct 111969: Oct 81970: Oct 91971: Oct 281972: Oct 171973: Oct 131974: Sep 301975: Oct 111976: Sep 291977: Oct 121978: Oct 71979: Oct 131980: Oct 141981: Oct 221982: Oct 71983: Oct 131984: Sep 261985: Sep 231986: Oct 111987: Oct 11988: Sep 191989: Sep 222019: Oct 112021: Oct 212022: Oct 72023: Oct 72024: Oct 142025: Oct 23

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 29Oct 23Apr 20Oct 23
2024May 3Oct 14Apr 21Oct 14
2023May 2Oct 7May 2Oct 7
2022Apr 28Oct 7Apr 27Oct 8
2021no dataOct 21no dataNov 1
2019no dataOct 11no dataOct 11
1990Apr 30no dataApr 17no data
1989May 5Sep 22Apr 17Oct 16
1988Apr 27Sep 19Apr 26Oct 3
1987Apr 21Oct 1Apr 2Oct 10
1986Apr 20Oct 11Apr 16Oct 12
1985Apr 26Sep 23Apr 7Sep 30
1984May 9Sep 26May 1Sep 29
1983May 14Oct 13Apr 16Oct 13
1982Apr 30Oct 7Apr 11Nov 4
1981May 10Oct 22May 10Oct 22
1980May 8Oct 14May 8Oct 26
1979May 13Oct 13May 1Oct 13
1978Apr 26Oct 7Apr 22Oct 16
1977Apr 7Oct 12Apr 1Oct 12
1976May 7Sep 29May 4Oct 16
1975Apr 21Oct 11Apr 20Oct 25
1974May 16Sep 30Apr 24Sep 30
1973May 3Oct 13Apr 17Oct 28
1972May 8Oct 17Apr 23Oct 18
1971May 3Oct 28Apr 14Oct 28
1970Apr 24Oct 9Apr 21Oct 10
1969Apr 29Oct 8Apr 1Oct 14
1968Apr 25Oct 11Apr 15Nov 6
1967May 7Sep 28May 6Oct 28
1966May 13Oct 15Apr 30Oct 29
1965May 28Sep 24Mar 31Sep 24
1964Apr 18Sep 27Apr 8Oct 6
1963May 22Oct 28Apr 30Nov 13
1962May 1Oct 25Apr 16Oct 25
1961May 1Sep 30May 1Oct 19
1960no dataSep 30no dataSep 30

"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.