Last Frost Day

Frost history / Rockwell City, IA

Rockwell City, IA: frost dates by year

Last spring and first fall frost at NOAA station USC00137161, 1951 to 2023, measured from daily minimum temperatures.

Elevation 1,214 ft, 42.397, -94.629. Download the data (JSON), NOAA daily records

Summary at 32°F

Last spring frostFirst fall frost
MedianApr 29Oct 7
EarliestApr 6 (1977)Sep 19 (1991)
LatestMay 22 (1963)Oct 29 (1963)
Trend0.6 days earlier per decade0.6 days later per decade
Years with data7368

At 28°F (hard freeze) the median last spring date is Apr 14 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 3019601970198019902000201020201951: Apr 261952: Apr 161953: May 131954: May 91955: Apr 71956: May 41957: May 41958: Apr 291959: Apr 221960: May 81961: May 21962: Apr 171963: May 221964: Apr 91965: Apr 281966: May 101967: May 41968: May 51969: Apr 291970: May 21971: May 31972: Apr 261973: Apr 281974: May 61975: Apr 201976: May 31977: Apr 61978: May 21979: May 121980: May 81981: May 101982: Apr 221983: May 151984: May 11985: Apr 91986: May 21987: Apr 111988: Apr 241989: May 61990: May 11991: Apr 101992: Apr 271993: Apr 201994: May 11995: Apr 271996: May 11997: May 151998: Apr 181999: Apr 192000: Apr 222001: Apr 192002: May 102003: Apr 112004: May 42005: May 52006: Apr 272007: Apr 142008: Apr 302009: Apr 212010: May 92011: May 42012: Apr 122013: May 122014: May 162015: Apr 232016: Apr 132017: Apr 302018: Apr 212019: Apr 292020: Apr 222021: Apr 232022: Apr 272023: Apr 26

First fall frost (32°F)

Sep 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: Oct 231963: Oct 291964: Sep 281965: Oct 121966: Oct 11967: Sep 291968: Oct 41969: Oct 141970: Oct 101971: Oct 281972: Sep 301973: Oct 161974: Sep 221975: Oct 11976: Oct 61977: Oct 91978: Oct 81979: Oct 131980: Oct 31981: Oct 21982: Oct 201983: Sep 211984: Sep 261985: Sep 261986: Oct 61987: Oct 31988: Oct 41989: Sep 231990: Oct 101991: Sep 191992: Oct 161993: Oct 91994: Oct 251995: Sep 221996: Oct 31997: Oct 201999: Oct 22000: Oct 62003: Sep 292004: Oct 22005: Oct 72006: Oct 122007: Oct 252008: Oct 162009: Oct 72011: Oct 192012: Oct 52013: Oct 192014: Oct 42015: Oct 182016: Oct 132017: Oct 272018: Oct 152019: Oct 122020: Oct 22021: Oct 222022: Sep 28

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
2023Apr 26no dataApr 25no data
2022Apr 27Sep 28Apr 27Oct 8
2021Apr 23Oct 22Apr 22Nov 1
2020Apr 22Oct 2Apr 16Oct 24
2019Apr 29Oct 12Apr 28Oct 12
2018Apr 21Oct 15Apr 20Oct 21
2017Apr 30Oct 27Apr 8Oct 29
2016Apr 13Oct 13Apr 13Nov 12
2015Apr 23Oct 18Mar 28Oct 30
2014May 16Oct 4Apr 18Oct 31
2013May 12Oct 19Apr 25Oct 25
2012Apr 12Oct 5Apr 12Oct 6
2011May 4Oct 19May 3Oct 19
2010May 9no dataMar 29no data
2009Apr 21Oct 7Apr 10Oct 10
2008Apr 30Oct 16Apr 29Oct 28
2007Apr 14Oct 25Apr 13Nov 6
2006Apr 27Oct 12Apr 10Oct 12
2005May 5Oct 7Apr 2Oct 24
2004May 4Oct 2Apr 14Oct 31
2003Apr 11Sep 29Apr 10Oct 2
2002May 10no dataMay 10no data
2001Apr 19no dataApr 19no data
2000Apr 22Oct 6Apr 9Oct 6
1999Apr 19Oct 2Apr 18Oct 4
1998Apr 18no dataMar 25no data
1997May 15Oct 20May 13Oct 21
1996May 1Oct 3Apr 23Oct 28
1995Apr 27Sep 22Apr 5Sep 22
1994May 1Oct 25Apr 7Oct 26
1993Apr 20Oct 9Apr 5Oct 10
1992Apr 27Oct 16Apr 13Oct 17
1991Apr 10Sep 19Apr 10Oct 7
1990May 1Oct 10May 1Oct 18
1989May 6Sep 23Apr 15Oct 18
1988Apr 24Oct 4Apr 19Oct 24
1987Apr 11Oct 3Apr 4Oct 11
1986May 2Oct 6Apr 22Oct 14
1985Apr 9Sep 26Apr 9Oct 1
1984May 1Sep 26Apr 1Sep 26
1983May 15Sep 21Apr 19Oct 13
1982Apr 22Oct 20Apr 21Oct 20
1981May 10Oct 2Mar 20Oct 19
1980May 8Oct 3Apr 14Oct 19
1979May 12Oct 13Apr 7Oct 13
1978May 2Oct 8Apr 21Oct 23
1977Apr 6Oct 9Apr 6Oct 16
1976May 3Oct 6May 3Oct 8
1975Apr 20Oct 1Apr 12Oct 25
1974May 6Sep 22Apr 8Oct 2
1973Apr 28Oct 16Apr 13Nov 4
1972Apr 26Sep 30Apr 8Oct 15
1971May 3Oct 28Apr 6Oct 31
1970May 2Oct 10Apr 4Oct 10
1969Apr 29Oct 14Mar 31Oct 14
1968May 5Oct 4Apr 25Oct 4
1967May 4Sep 29May 3Oct 11
1966May 10Oct 1May 10Oct 29
1965Apr 28Oct 12Apr 16Oct 24
1964Apr 9Sep 28Apr 9Oct 9
1963May 22Oct 29Apr 4Oct 29
1962Apr 17Oct 23Apr 17Oct 24
1961May 2Sep 28Apr 18Oct 1
1960May 8Oct 19Apr 10Oct 19
1959Apr 22Oct 9Apr 13Oct 12
1958Apr 29Oct 1Apr 29Oct 26
1957May 4Oct 10Apr 14Oct 25
1956May 4Sep 30Apr 30Nov 8
1955Apr 7Oct 15Apr 7Oct 15
1954May 9Oct 16May 7Oct 18
1953May 13Oct 7Apr 20Oct 26
1952Apr 16Oct 4Apr 11Oct 5
1951Apr 26Sep 28Apr 23Oct 23

"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.