Last Frost Day

Frost history / Independence #1, IA

Independence #1, IA: frost dates by year

Last spring and first fall frost at NOAA station USC00134049, 1981 to 2008, measured from daily minimum temperatures.

Elevation 1,010 ft, 42.527, -91.878. Download the data (JSON), NOAA daily records

Summary at 32°F

Last spring frostFirst fall frost
MedianApr 26Oct 3
EarliestMar 27 (1999)Sep 15 (1984)
LatestMay 20 (2002)Nov 1 (1994)
Trend0.6 days later per decade2.5 days later per decade
Years with data2426

At 28°F (hard freeze) the median last spring date is Apr 13 and the median first fall date is Oct 15.

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 16Mar 31Apr 15Apr 30May 15May 30199020001982: Apr 271983: May 81984: May 21985: Apr 151986: Apr 231987: Apr 111988: Apr 281989: May 71990: Apr 181991: Apr 231992: May 61993: Apr 211994: May 11995: Apr 251996: May 131997: May 161998: Apr 171999: Mar 272000: Apr 122001: Apr 182002: May 202003: Apr 232004: May 62008: Apr 30

First fall frost (32°F)

Aug 28Sep 12Sep 27Oct 12Oct 27Nov 11199020001981: Sep 281982: Oct 161983: Sep 221984: Sep 151985: Sep 241986: Oct 61987: Oct 31988: Oct 31989: Sep 231990: Oct 111991: Sep 191992: Sep 291993: Oct 51994: Nov 11995: Sep 221996: Oct 31997: Oct 141998: Oct 221999: Oct 42000: Oct 62001: Oct 62002: Oct 72003: Sep 292004: Oct 22007: Sep 152008: Oct 15

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
2008Apr 30Oct 15Apr 14Oct 28
2007no dataSep 15no dataOct 28
2004May 6Oct 2May 4Oct 5
2003Apr 23Sep 29Apr 23Sep 29
2002May 20Oct 7Apr 7Oct 14
2001Apr 18Oct 6Apr 18Oct 17
2000Apr 12Oct 6Apr 12Oct 7
1999Mar 27Oct 4Mar 26Oct 18
1998Apr 17Oct 22Mar 24Oct 22
1997May 16Oct 14Apr 17Oct 22
1996May 13Oct 3Apr 27Oct 19
1995Apr 25Sep 22Apr 5Oct 15
1994May 1Nov 1Apr 7Nov 1
1993Apr 21Oct 5Apr 10Oct 10
1992May 6Sep 29Apr 12Oct 17
1991Apr 23Sep 19Apr 1Sep 20
1990Apr 18Oct 11Apr 18Oct 19
1989May 7Sep 23May 6Sep 23
1988Apr 28Oct 3Apr 24Oct 5
1987Apr 11Oct 3Apr 4Oct 3
1986Apr 23Oct 6Apr 22Oct 15
1985Apr 15Sep 24Apr 8Sep 27
1984May 2Sep 15Apr 6Sep 26
1983May 8Sep 22Apr 20Sep 23
1982Apr 27Oct 16Apr 21Oct 21
1981no dataSep 28no dataOct 2

"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.