Last Frost Day

Frost history / Storm Lake, IA

Storm Lake, IA: frost dates by year

Last spring and first fall frost at NOAA station USC00137979, 1951 to 2025, measured from daily minimum temperatures.

Elevation 1,442 ft, 42.647, -95.193. Download the data (JSON), NOAA daily records

Summary at 32°F

Last spring frostFirst fall frost
MedianMay 1Oct 9
EarliestApr 7 (1977)Sep 16 (1966)
LatestMay 26 (1971)Nov 3 (2007)
Trend2.6 days earlier per decade1.8 days later per decade
Years with data6565

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

Mar 31Apr 15Apr 30May 15May 30Jun 1419601970198019902000201020201951: May 61953: May 131954: May 91955: May 81956: May 41957: May 51958: Apr 291959: May 151960: May 111961: May 31962: Apr 201963: May 231964: Apr 231965: Apr 291966: May 131967: May 201968: May 51969: Apr 301970: May 21971: May 261972: Apr 261973: May 21974: May 71975: Apr 221976: May 81977: Apr 71978: May 21979: May 121980: May 91981: May 121982: Apr 231983: May 151984: May 91985: Apr 91986: May 31987: Apr 111988: Apr 281989: May 71990: May 21991: Apr 111992: Apr 281993: Apr 91994: May 12003: Apr 102004: May 32005: May 42006: Apr 102007: Apr 142008: Apr 292009: Apr 142010: Apr 82011: May 32012: Apr 122014: May 172015: Apr 232016: Apr 132017: May 22018: Apr 212019: Apr 292020: Apr 212021: Apr 232022: Apr 272023: Apr 252024: Apr 212025: Apr 15

First fall frost (32°F)

Aug 28Sep 12Sep 27Oct 12Oct 27Nov 1119601970198019902000201020201951: Sep 281952: Oct 41953: Oct 71954: Oct 161955: Oct 151956: Sep 301957: Oct 101958: Oct 11959: Oct 91960: Oct 191961: Sep 281962: Sep 201963: Oct 291964: Sep 271965: Sep 241966: Sep 161967: Sep 281969: Oct 131970: Oct 91971: Oct 281972: Oct 151973: Oct 171974: Sep 221975: Oct 251976: Oct 61977: Oct 61978: Oct 71979: Oct 91980: Oct 31981: Oct 21982: Oct 171983: Sep 221984: Sep 261985: Sep 251986: Oct 61987: Oct 31988: Oct 41989: Sep 231990: Oct 111991: Sep 191992: Oct 151993: Sep 291994: Oct 122004: Oct 22005: Oct 72006: Oct 122007: Nov 32008: Oct 162009: Oct 92010: Oct 172011: Oct 182012: Sep 222013: Oct 222014: Oct 52015: Oct 302016: Oct 142017: Oct 272018: Oct 122019: Oct 112020: Oct 152021: Oct 232022: Oct 152023: Oct 272024: Oct 162025: 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 15Oct 23Apr 9Nov 9
2024Apr 21Oct 16Apr 21Nov 15
2023Apr 25Oct 27Apr 24Oct 28
2022Apr 27Oct 15Apr 26Oct 17
2021Apr 23Oct 23Apr 22Nov 2
2020Apr 21Oct 15Apr 16Oct 24
2019Apr 29Oct 11Apr 15Oct 13
2018Apr 21Oct 12Apr 21Oct 15
2017May 2Oct 27Apr 29Oct 28
2016Apr 13Oct 14Apr 13Nov 19
2015Apr 23Oct 30Apr 23Nov 14
2014May 17Oct 5Apr 18Nov 1
2013no dataOct 22no dataOct 26
2012Apr 12Sep 22Apr 11Oct 5
2011May 3Oct 18May 3Oct 19
2010Apr 8Oct 17Mar 26Oct 28
2009Apr 14Oct 9Apr 14Oct 11
2008Apr 29Oct 16Apr 28Oct 28
2007Apr 14Nov 3Apr 14Nov 6
2006Apr 10Oct 12Apr 8Oct 12
2005May 4Oct 7May 3Oct 24
2004May 3Oct 2Apr 13Oct 31
2003Apr 10no dataApr 10no data
1994May 1Oct 12May 1Oct 25
1993Apr 9Sep 29Apr 5Oct 10
1992Apr 28Oct 15Apr 23Oct 17
1991Apr 11Sep 19Apr 11Oct 19
1990May 2Oct 11Apr 18Oct 18
1989May 7Sep 23May 6Sep 24
1988Apr 28Oct 4Apr 20Oct 5
1987Apr 11Oct 3Apr 5Oct 10
1986May 3Oct 6Apr 23Oct 14
1985Apr 9Sep 25Apr 9Nov 2
1984May 9Sep 26Apr 7Sep 26
1983May 15Sep 22Apr 20Oct 13
1982Apr 23Oct 17Apr 12Oct 20
1981May 12Oct 2Apr 15Oct 22
1980May 9Oct 3May 8Oct 4
1979May 12Oct 9May 2Oct 13
1978May 2Oct 7Apr 22Oct 16
1977Apr 7Oct 6Apr 7Oct 16
1976May 8Oct 6May 4Oct 6
1975Apr 22Oct 25Apr 13Oct 29
1974May 7Sep 22Apr 9Oct 1
1973May 2Oct 17Apr 14Oct 29
1972Apr 26Oct 15Apr 9Oct 15
1971May 26Oct 28Apr 14Oct 31
1970May 2Oct 9Apr 5Oct 10
1969Apr 30Oct 13Apr 23Oct 22
1968May 5no dataApr 25no data
1967May 20Sep 28May 5Oct 11
1966May 13Sep 16May 11Oct 2
1965Apr 29Sep 24Apr 28Oct 24
1964Apr 23Sep 27Apr 9Oct 9
1963May 23Oct 29May 22Oct 29
1962Apr 20Sep 20Apr 20Oct 24
1961May 3Sep 28May 2Oct 1
1960May 11Oct 19May 1Oct 19
1959May 15Oct 9Apr 13Oct 9
1958Apr 29Oct 1Apr 29Oct 11
1957May 5Oct 10May 4Oct 10
1956May 4Sep 30Apr 30Oct 9
1955May 8Oct 15May 8Oct 24
1954May 9Oct 16May 7Oct 18
1953May 13Oct 7Apr 20Oct 7
1952no dataOct 4no dataOct 5
1951May 6Sep 28Apr 23Sep 28

"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.