Last Frost Day

Frost history / Lacon, IL

Lacon, IL: frost dates by year

Last spring and first fall frost at NOAA station USC00114805, 1959 to 2009, measured from daily minimum temperatures.

Elevation 458 ft, 41.019, -89.415. Download the data (JSON), NOAA daily records

Summary at 32°F

Last spring frostFirst fall frost
MedianApr 22Oct 11
EarliestApr 2 (1991)Sep 20 (1991)
LatestMay 21 (2002)Nov 5 (1983)
Trendlittle change (less than half a day per decade)little change (less than half a day per decade)
Years with data4446

At 28°F (hard freeze) the median last spring date is Apr 12 and the median first fall date is Oct 22.

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 30196019701980199020001960: May 121962: Apr 201965: Apr 31966: May 101967: May 31968: Apr 151969: Apr 291970: Apr 101972: Apr 261973: Apr 131974: May 71975: Apr 151976: May 71977: Apr 291978: May 31979: Apr 101980: Apr 261981: May 121982: Apr 221983: May 91984: Apr 71985: Apr 91988: Apr 211989: May 71990: Apr 181991: Apr 21992: Apr 281993: Apr 101994: Apr 71995: Apr 241996: Apr 271997: May 161998: Apr 171999: Apr 192000: Apr 122001: Apr 182002: May 212003: Apr 232004: May 32005: May 162006: Apr 262007: Apr 162008: Apr 152009: Apr 15

First fall frost (32°F)

Sep 12Sep 27Oct 12Oct 27Nov 11196019701980199020001959: Oct 121960: Oct 201961: Oct 21962: Oct 241964: Oct 61965: Oct 241966: Oct 61967: Sep 291968: Oct 41969: Oct 141970: Oct 161971: Nov 11972: Sep 301973: Nov 31974: Sep 231975: Oct 21976: Oct 81977: Oct 131978: Oct 141979: Oct 131980: Oct 51981: Oct 191982: Oct 211983: Nov 51984: Sep 301988: Oct 61989: Sep 241990: Oct 111991: Sep 201992: Oct 171993: Oct 101994: Oct 101995: Sep 231996: Oct 91997: Oct 151998: Oct 141999: Oct 142000: Oct 72001: Oct 62002: Oct 142003: Oct 22004: Oct 52005: Oct 162006: Oct 122007: Oct 282008: Oct 21

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

"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.