Last Frost Day

Frost history / Tipton, IA

Tipton, IA: frost dates by year

Last spring and first fall frost at NOAA station USC00138266, 1951 to 2009, measured from daily minimum temperatures.

Elevation 820 ft, 41.780, -91.127. Download the data (JSON), NOAA daily records

Summary at 32°F

Last spring frostFirst fall frost
MedianApr 30Oct 5
EarliestMar 30 (1999)Sep 20 (1956)
LatestMay 29 (1984)Oct 30 (1973)
Trend1.2 days earlier per decadelittle change (less than half a day per decade)
Years with data5658

At 28°F (hard freeze) the median last spring date is Apr 13 and the median first fall date is Oct 16.

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 30Jun 14196019701980199020001952: Apr 161953: May 131954: May 71955: Apr 71956: Apr 301957: May 41958: May 51959: Apr 221960: May 81961: May 261962: Apr 201963: May 221964: Apr 101965: Apr 191966: May 111967: May 71968: Apr 251969: Apr 291970: Apr 101971: May 131972: Apr 261973: Apr 271974: May 61975: May 11976: May 41978: May 21979: May 11980: Apr 261981: May 121982: Apr 281983: May 91984: May 291985: Apr 111986: Apr 231987: Apr 111988: Apr 241989: May 71990: Apr 181991: Apr 101992: May 71993: Apr 211994: May 21995: Apr 251996: May 21997: May 161998: Apr 171999: Mar 302000: Apr 132001: Apr 192002: May 32003: Apr 262004: May 32005: May 52006: May 62008: Apr 292009: Apr 15

First fall frost (32°F)

Sep 12Sep 27Oct 12Oct 27Nov 11196019701980199020001951: Sep 281952: Oct 31953: Oct 71954: Oct 181955: Oct 161956: Sep 201957: Oct 101958: Oct 11959: Oct 121960: Oct 191961: Sep 281962: Sep 201963: Oct 281964: Oct 51965: Oct 241966: Oct 171967: Sep 291968: Oct 41969: Oct 141970: Oct 41971: Oct 71972: Sep 301973: Oct 301974: Sep 221975: Sep 251976: Sep 221977: Oct 61978: Oct 141979: Oct 71980: Oct 51981: Oct 21982: Oct 161983: Sep 221984: Sep 291985: Sep 271986: Oct 121987: Oct 31988: Oct 41989: Sep 241990: Oct 111991: Sep 201992: Sep 291993: Oct 51994: Oct 101995: Sep 221996: Oct 31997: Oct 141998: Oct 221999: Oct 142000: Oct 72001: Sep 252002: Oct 132003: Sep 302004: Oct 22005: Oct 82007: Oct 252008: Oct 182009: Oct 10

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

"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.