Last Frost Day

Frost history / Sioux Ctr 2 Se, IA

Sioux Ctr 2 Se, IA: frost dates by year

Last spring and first fall frost at NOAA station USC00137700, 1953 to 2025, measured from daily minimum temperatures.

Elevation 1,360 ft, 43.056, -96.153. Download the data (JSON), NOAA daily records

Summary at 32°F

Last spring frostFirst fall frost
MedianMay 3Oct 1
EarliestApr 6 (1977)Sep 3 (1974)
LatestMay 28 (1965)Oct 28 (1963)
Trend1.3 days earlier per decadelittle change (less than half a day per decade)
Years with data6968

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 31Apr 15Apr 30May 15May 30Jun 1419601970198019902000201020201954: May 91957: May 41958: Apr 291959: May 151960: May 111961: May 91962: Apr 191963: May 221964: Apr 221965: May 281966: May 111967: May 91968: May 181969: May 121970: May 21971: May 121972: Apr 251973: May 171974: May 61976: May 81977: Apr 61978: May 31979: May 41980: May 91981: May 111982: Apr 271983: May 151984: May 11985: Apr 101986: Apr 221987: Apr 231988: Apr 271989: May 71990: May 21991: May 71992: May 61993: Apr 261994: May 11995: May 21996: May 11997: May 151998: Apr 191999: Apr 192000: Apr 212001: Apr 242002: May 102003: Apr 222004: May 142005: May 152006: Apr 92007: Apr 152008: Apr 292009: Apr 282010: May 92011: May 32012: Apr 232013: May 122014: May 162015: Apr 222016: May 142017: May 12018: Apr 202019: Apr 282020: May 92021: May 112022: May 42023: May 32024: Apr 212025: Apr 19

First fall frost (32°F)

Aug 28Sep 12Sep 27Oct 12Oct 27Nov 1119601970198019902000201020201953: Oct 261956: Sep 301957: Oct 191959: Oct 81960: Oct 161961: Sep 281962: Sep 201963: Oct 281964: Sep 271965: Sep 241966: Oct 11967: Sep 281968: Oct 41969: Sep 231970: Oct 91971: Sep 191972: Sep 301974: Sep 31975: Sep 251976: Sep 281977: Oct 31978: Oct 71979: Oct 91980: Oct 31981: Oct 21982: Oct 71983: Sep 211984: Sep 261985: Sep 261986: Oct 61987: Oct 31988: Oct 41989: Sep 231990: Sep 231991: Sep 191992: Sep 281993: Sep 151994: Oct 251995: Sep 221996: Oct 31997: Oct 141998: Oct 11999: Sep 212000: Sep 212001: Sep 252002: Sep 242003: Sep 252004: Oct 22005: Sep 292006: Sep 202007: Sep 152008: Oct 162009: Oct 72010: Oct 32011: Sep 152012: Sep 232013: Oct 132014: Sep 132015: Oct 162016: Oct 132017: Oct 112018: Oct 42020: Oct 22021: Oct 222022: Sep 282023: Oct 102024: Oct 142025: Oct 22

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 19Oct 22Apr 8Oct 22
2024Apr 21Oct 14Apr 5Oct 16
2023May 3Oct 10Apr 25Oct 27
2022May 4Sep 28Apr 26Oct 8
2021May 11Oct 22Apr 22Nov 1
2020May 9Oct 2Apr 21Oct 4
2019Apr 28no dataApr 27no data
2018Apr 20Oct 4Apr 19Oct 14
2017May 1Oct 11Apr 11Oct 11
2016May 14Oct 13Apr 12Oct 13
2015Apr 22Oct 16Apr 22Oct 30
2014May 16Sep 13May 16Oct 11
2013May 12Oct 13May 3Oct 23
2012Apr 23Sep 23Apr 11Sep 23
2011May 3Sep 15May 3Oct 17
2010May 9Oct 3Apr 8Oct 29
2009Apr 28Oct 7Apr 14Oct 9
2008Apr 29Oct 16Apr 29Oct 16
2007Apr 15Sep 15Apr 14Oct 26
2006Apr 9Sep 20Apr 8Oct 12
2005May 15Sep 29May 4Oct 7
2004May 14Oct 2Apr 13Oct 2
2003Apr 22Sep 25Apr 9Oct 1
2002May 10Sep 24Apr 26Oct 13
2001Apr 24Sep 25Apr 18Oct 6
2000Apr 21Sep 21Apr 9Sep 25
1999Apr 19Sep 21Apr 18Sep 21
1998Apr 19Oct 1Apr 17Nov 4
1997May 15Oct 14May 13Oct 20
1996May 1Oct 3Apr 30Oct 3
1995May 2Sep 22Apr 10Sep 22
1994May 1Oct 25Apr 29Oct 25
1993Apr 26Sep 15Apr 21Oct 9
1992May 6Sep 28Apr 27Oct 17
1991May 7Sep 19Apr 10Sep 19
1990May 2Sep 23May 1Oct 10
1989May 7Sep 23May 7Oct 3
1988Apr 27Oct 4Apr 19Oct 4
1987Apr 23Oct 3Apr 5Oct 3
1986Apr 22Oct 6Apr 22Oct 13
1985Apr 10Sep 26Apr 9Oct 10
1984May 1Sep 26Apr 1Sep 26
1983May 15Sep 21Apr 18Sep 23
1982Apr 27Oct 7Apr 22Oct 20
1981May 11Oct 2Apr 15Oct 2
1980May 9Oct 3May 8Oct 4
1979May 4Oct 9Apr 28Oct 13
1978May 3Oct 7Apr 21Oct 16
1977Apr 6Oct 3Apr 6Oct 6
1976May 8Sep 28May 3Oct 6
1975no dataSep 25no dataOct 18
1974May 6Sep 3Apr 15Sep 22
1973May 17no dataApr 13no data
1972Apr 25Sep 30Apr 25Oct 15
1971May 12Sep 19Apr 14Oct 31
1970May 2Oct 9May 2Oct 10
1969May 12Sep 23May 12Oct 14
1968May 18Oct 4May 5Oct 4
1967May 9Sep 28May 9Sep 28
1966May 11Oct 1May 10Oct 1
1965May 28Sep 24Apr 28Sep 26
1964Apr 22Sep 27Apr 8Oct 9
1963May 22Oct 28May 22Oct 29
1962Apr 19Sep 20Apr 17Oct 23
1961May 9Sep 28May 2Oct 1
1960May 11Oct 16Apr 30Oct 19
1959May 15Oct 8May 15Oct 9
1958Apr 29no dataApr 29no data
1957May 4Oct 19Apr 14Oct 25
1956no dataSep 30no dataOct 9
1954May 9no dataMay 9no data
1953no dataOct 26no dataOct 26

"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.