Last Frost Day

Frost history / Waukon, IA

Waukon, IA: frost dates by year

Last spring and first fall frost at NOAA station USC00138755, 1951 to 2025, measured from daily minimum temperatures.

Elevation 1,275 ft, 43.274, -91.471. Download the data (JSON), NOAA daily records

Summary at 32°F

Last spring frostFirst fall frost
MedianMay 1Oct 7
EarliestApr 5 (1987)Sep 16 (2011)
LatestMay 29 (1965)Oct 31 (1971)
Trend1.8 days earlier per decade0.8 days later per decade
Years with data5555

At 28°F (hard freeze) the median last spring date is Apr 16 and the median first fall date is Oct 19.

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: Apr 231952: Apr 151953: May 131954: May 91955: May 81956: May 161957: May 41958: May 51959: Apr 201960: May 101961: May 261962: Apr 201963: May 11964: Apr 151965: May 291966: May 111967: May 221968: May 51969: Apr 291970: May 61971: Apr 241972: Apr 241973: Apr 161974: May 101975: Apr 221976: May 41977: May 91978: May 11979: Apr 301980: Apr 241981: May 111982: Apr 221983: May 81984: May 81985: Apr 91986: Apr 221987: Apr 51988: Apr 271989: May 61990: May 11991: Apr 141997: May 202003: May 242004: May 42005: May 42006: Apr 102007: Apr 142008: May 12009: Apr 202010: Apr 102011: May 32012: Apr 182023: Apr 272024: Apr 242025: Apr 17

First fall frost (32°F)

Aug 28Sep 12Sep 27Oct 12Oct 27Nov 1119601970198019902000201020201951: Sep 281952: Oct 31953: Oct 71954: Oct 71955: Oct 141956: Sep 201957: Sep 271958: Oct 11959: Oct 91960: Oct 191961: Sep 281962: Oct 231963: Oct 291964: Oct 61965: Oct 121966: Oct 161967: Sep 291968: Oct 41969: Oct 141970: Oct 101971: Oct 311972: Sep 301973: Oct 301974: Sep 221975: Oct 21976: Oct 61977: Oct 111978: Oct 81979: Oct 71980: Oct 51981: Oct 21982: Oct 161983: Oct 131984: Sep 261985: Oct 61986: Oct 61987: Oct 31988: Oct 41989: Sep 231990: Oct 111996: Oct 21997: Oct 132002: Oct 72003: Oct 12004: Oct 32005: Oct 82006: Oct 122007: Oct 282008: Oct 212009: Oct 102010: Oct 292011: Sep 162012: Oct 72024: Oct 152025: 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 17Oct 23Apr 16Oct 23
2024Apr 24Oct 15Apr 21Nov 1
2023Apr 27no dataApr 23no data
2012Apr 18Oct 7Apr 12Oct 10
2011May 3Sep 16Apr 6Nov 5
2010Apr 10Oct 29Mar 30Oct 29
2009Apr 20Oct 10Apr 9Oct 11
2008May 1Oct 21Apr 16Oct 28
2007Apr 14Oct 28Apr 14Nov 7
2006Apr 10Oct 12Apr 9Oct 12
2005May 4Oct 8May 4Nov 10
2004May 4Oct 3May 4Oct 17
2003May 24Oct 1Apr 10Oct 2
2002no dataOct 7no dataOct 13
1997May 20Oct 13May 15Oct 14
1996no dataOct 2no dataOct 2
1991Apr 14no dataMar 30no data
1990May 1Oct 11Apr 18Oct 19
1989May 6Sep 23May 6Oct 18
1988Apr 27Oct 4Apr 24Oct 4
1987Apr 5Oct 3Apr 4Oct 3
1986Apr 22Oct 6Apr 22Nov 2
1985Apr 9Oct 6Apr 9Nov 5
1984May 8Sep 26Mar 31Sep 26
1983May 8Oct 13Apr 20Oct 13
1982Apr 22Oct 16Apr 21Oct 21
1981May 11Oct 2May 10Oct 19
1980Apr 24Oct 5Apr 24Oct 12
1979Apr 30Oct 7Apr 14Oct 24
1978May 1Oct 8May 1Nov 7
1977May 9Oct 11Apr 8Oct 13
1976May 4Oct 6Apr 12Oct 8
1975Apr 22Oct 2Apr 12Oct 29
1974May 10Sep 22Apr 8Oct 2
1973Apr 16Oct 30Apr 13Nov 5
1972Apr 24Sep 30Apr 9Oct 17
1971Apr 24Oct 31Apr 24Nov 3
1970May 6Oct 10Apr 4Nov 14
1969Apr 29Oct 14Apr 1Oct 14
1968May 5Oct 4Apr 15Oct 29
1967May 22Sep 29May 3Oct 26
1966May 11Oct 16May 10Oct 17
1965May 29Oct 12Apr 3Oct 24
1964Apr 15Oct 6Apr 9Oct 9
1963May 1Oct 29Apr 30Nov 1
1962Apr 20Oct 23Apr 20Oct 24
1961May 26Sep 28May 1Sep 28
1960May 10Oct 19Apr 18Oct 19
1959Apr 20Oct 9Apr 11Oct 12
1958May 5Oct 1Apr 29Oct 1
1957May 4Sep 27Apr 14Oct 25
1956May 16Sep 20Apr 30Oct 9
1955May 8Oct 14Apr 7Oct 16
1954May 9Oct 7May 7Oct 20
1953May 13Oct 7May 13Oct 27
1952Apr 15Oct 3Apr 11Oct 3
1951Apr 23Sep 28Apr 23Oct 27

"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.