Last Frost Day

Frost history / Le Mars, IA

Le Mars, IA: frost dates by year

Last spring and first fall frost at NOAA station USC00134735, 1951 to 2025, measured from daily minimum temperatures.

Elevation 1,195 ft, 42.782, -96.146. Download the data (JSON), NOAA daily records

Summary at 32°F

Last spring frostFirst fall frost
MedianMay 2Oct 3
EarliestApr 6 (1977)Sep 11 (1955)
LatestMay 23 (1963)Oct 28 (1963)
Trend1.3 days earlier per decade1.6 days later per decade
Years with data7374

At 28°F (hard freeze) the median last spring date is Apr 20 and the median first fall date is Oct 11.

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 3019601970198019902000201020201951: Apr 231952: Apr 241953: May 131954: May 71955: Apr 71956: May 41957: May 111958: May 81959: May 151960: May 121961: May 91962: May 21963: May 231964: Apr 221965: Apr 281966: May 101967: May 91968: May 171969: May 121970: May 21971: May 121972: Apr 251973: May 171974: Apr 231975: Apr 201976: May 71977: Apr 61978: May 31979: May 41980: May 91981: May 111982: Apr 271983: May 151984: May 91985: Apr 101986: Apr 221987: Apr 231988: Apr 281989: May 61990: May 21991: Apr 111992: Apr 281993: Apr 221994: May 11995: May 21996: Apr 301997: May 141998: Apr 151999: Apr 182000: Apr 162001: Apr 232002: May 22003: Apr 122005: May 42006: Apr 92007: Apr 162008: Apr 292010: Apr 172011: May 42012: Apr 242013: May 122014: May 162015: Apr 232016: Apr 132017: May 22018: Apr 282019: Apr 292020: May 82021: May 112022: Apr 272023: May 32024: Apr 212025: Apr 20

First fall frost (32°F)

Aug 28Sep 12Sep 27Oct 12Oct 27Nov 1119601970198019902000201020201951: Sep 281952: Oct 41953: Oct 41954: Sep 221955: Sep 111956: Sep 301957: Oct 101958: Sep 271959: Sep 301960: Oct 161961: Sep 151962: Sep 201963: Oct 281964: Oct 51965: Sep 241966: Sep 151967: Sep 241968: Oct 31969: Oct 81970: Oct 91971: Sep 171972: Sep 301974: Sep 221975: Sep 251976: Oct 61977: Oct 31978: Oct 71979: Oct 131980: Oct 31981: Oct 21982: Oct 161983: Sep 211984: Sep 261985: Sep 261986: Oct 61987: Oct 31988: Oct 41989: Sep 231990: Oct 101991: Sep 191992: Oct 161993: Sep 151994: Oct 251995: Sep 211996: Sep 241997: Oct 131998: Sep 301999: Sep 212000: Sep 242001: Oct 52002: Oct 72003: Oct 12004: Oct 22005: Sep 302006: Sep 202007: Oct 262008: Oct 162009: Oct 72010: Oct 172011: Sep 152012: Sep 232013: Oct 132014: Oct 42015: Oct 162016: Oct 132017: Oct 112018: Oct 42019: Oct 102020: Oct 22021: Oct 222022: Oct 72023: Oct 72024: 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 20Oct 22Apr 9Nov 9
2024Apr 21Oct 14Apr 5Oct 15
2023May 3Oct 7Apr 25Oct 28
2022Apr 27Oct 7Apr 27Oct 8
2021May 11Oct 22Apr 22Nov 1
2020May 8Oct 2Apr 17Oct 24
2019Apr 29Oct 10Apr 14Oct 11
2018Apr 28Oct 4Apr 20Oct 15
2017May 2Oct 11Apr 11Oct 11
2016Apr 13Oct 13Apr 12Oct 13
2015Apr 23Oct 16Apr 22Nov 13
2014May 16Oct 4May 16Oct 11
2013May 12Oct 13May 3Oct 19
2012Apr 24Sep 23Apr 13Sep 23
2011May 4Sep 15May 3Oct 19
2010Apr 17Oct 17Mar 28Oct 29
2009no dataOct 7no dataOct 9
2008Apr 29Oct 16Apr 28Oct 27
2007Apr 16Oct 26Apr 14Nov 1
2006Apr 9Sep 20Apr 9Oct 12
2005May 4Sep 30May 3Oct 22
2004no dataOct 2no dataOct 2
2003Apr 12Oct 1Apr 10Oct 1
2002May 2Oct 7Apr 9Oct 13
2001Apr 23Oct 5Apr 17Oct 5
2000Apr 16Sep 24Apr 8Oct 5
1999Apr 18Sep 21Apr 17Oct 1
1998Apr 15Sep 30Apr 3Nov 3
1997May 14Oct 13May 13Oct 19
1996Apr 30Sep 24Apr 25Oct 28
1995May 2Sep 21Apr 6Sep 21
1994May 1Oct 25May 1Oct 25
1993Apr 22Sep 15Apr 6Oct 9
1992Apr 28Oct 16Apr 27Oct 18
1991Apr 11Sep 19Apr 11Sep 19
1990May 2Oct 10Apr 18Oct 10
1989May 6Sep 23Apr 15Oct 7
1988Apr 28Oct 4Apr 19Oct 5
1987Apr 23Oct 3Apr 6Oct 3
1986Apr 22Oct 6Apr 22Oct 13
1985Apr 10Sep 26Apr 9Oct 10
1984May 9Sep 26Apr 6Sep 26
1983May 15Sep 21May 15Sep 23
1982Apr 27Oct 16Apr 27Oct 20
1981May 11Oct 2Apr 14Oct 2
1980May 9Oct 3Apr 14Oct 26
1979May 4Oct 13Apr 28Oct 13
1978May 3Oct 7May 2Oct 7
1977Apr 6Oct 3Apr 6Oct 16
1976May 7Oct 6May 3Oct 6
1975Apr 20Sep 25Apr 11Oct 25
1974Apr 23Sep 22Apr 16Sep 22
1973May 17no dataMay 17no data
1972Apr 25Sep 30Apr 15Oct 15
1971May 12Sep 17May 3Sep 23
1970May 2Oct 9May 2Oct 10
1969May 12Oct 8May 12Oct 14
1968May 17Oct 3May 5Oct 4
1967May 9Sep 24May 9Sep 28
1966May 10Sep 15May 9Oct 5
1965Apr 28Sep 24Apr 28Oct 12
1964Apr 22Oct 5Apr 9Oct 9
1963May 23Oct 28May 23Oct 29
1962May 2Sep 20Apr 19Sep 20
1961May 9Sep 15May 9Sep 25
1960May 12Oct 16May 8Oct 16
1959May 15Sep 30May 15Oct 12
1958May 8Sep 27Apr 29Sep 28
1957May 11Oct 10Apr 14Oct 18
1956May 4Sep 30Apr 30Sep 30
1955Apr 7Sep 11Apr 7Oct 15
1954May 7Sep 22May 5Oct 30
1953May 13Oct 4Apr 20Oct 26
1952Apr 24Oct 4Apr 15Oct 5
1951Apr 23Sep 28Apr 22Sep 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.