Last Frost Day

Frost history / Glenwood 3SW, IA

Glenwood 3SW, IA: frost dates by year

Last spring and first fall frost at NOAA station USC00133290, 1951 to 2008, measured from daily minimum temperatures.

Elevation 980 ft, 41.010, -95.774. Download the data (JSON), NOAA daily records

Summary at 32°F

Last spring frostFirst fall frost
MedianApr 25Oct 6
EarliestApr 6 (1969)Sep 18 (1973)
LatestMay 15 (1983)Nov 6 (1998)
Trend0.9 days earlier per decadelittle change (less than half a day per decade)
Years with data5454

At 28°F (hard freeze) the median last spring date is Apr 12 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 31Apr 15Apr 30May 15May 30196019701980199020001951: May 71952: May 131953: Apr 271955: Apr 71956: Apr 301959: May 151960: Apr 181961: Apr 281962: Apr 151963: Apr 231964: Apr 91965: Apr 281966: May 91967: May 31968: Apr 251969: Apr 61970: Apr 231971: Apr 61972: Apr 251973: May 151974: Apr 171975: Apr 201976: May 81977: Apr 261978: May 31979: Apr 281980: May 91981: May 111982: Apr 221983: May 151984: Apr 191985: Apr 91986: Apr 221987: Apr 121988: Apr 281989: May 71990: May 131991: Apr 101993: Apr 91994: May 11995: Apr 211996: Apr 241997: May 141998: Apr 181999: Apr 182000: Apr 222001: Apr 252002: Apr 232003: Apr 92004: May 42005: May 42006: Apr 92007: Apr 152008: Apr 29

First fall frost (32°F)

Sep 12Sep 27Oct 12Oct 27Nov 11196019701980199020001951: Sep 281953: Sep 221954: Oct 301955: Oct 81956: Sep 301958: Oct 11959: Oct 91960: Oct 161961: Oct 11962: Oct 251963: Oct 291964: Oct 51965: Sep 241966: Oct 161967: Oct 111968: Oct 251969: Oct 141970: Oct 91971: Oct 311972: Sep 301973: Sep 181974: Sep 291975: Sep 251976: Oct 61977: Oct 91978: Oct 71979: Oct 51980: Oct 31981: Oct 21982: Oct 141983: Sep 211984: Sep 261985: Oct 11986: Oct 131987: Oct 31988: Oct 41989: Sep 241990: Oct 101991: Sep 191992: Oct 111993: Oct 101994: Oct 241996: Oct 231997: Oct 141998: Nov 61999: Oct 42000: Oct 62001: Oct 62002: Oct 72003: Sep 252004: Oct 22005: Sep 292006: Oct 122007: 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
2008Apr 29no dataApr 15no data
2007Apr 15Oct 23Apr 10Oct 28
2006Apr 9Oct 12Mar 26Oct 12
2005May 4Sep 29Apr 30Oct 7
2004May 4Oct 2Apr 14Oct 2
2003Apr 9Sep 25Apr 9Sep 28
2002Apr 23Oct 7Apr 6Oct 13
2001Apr 25Oct 6Apr 16Oct 16
2000Apr 22Oct 6Apr 12Oct 6
1999Apr 18Oct 4Mar 27Oct 4
1998Apr 18Nov 6Mar 24Nov 6
1997May 14Oct 14Apr 18Oct 27
1996Apr 24Oct 23Apr 9Oct 31
1995Apr 21no dataApr 5no data
1994May 1Oct 24Apr 7Oct 25
1993Apr 9Oct 10Apr 5Oct 10
1992no dataOct 11no dataOct 17
1991Apr 10Sep 19Mar 30Sep 19
1990May 13Oct 10Apr 13Oct 10
1989May 7Sep 24Apr 20Oct 7
1988Apr 28Oct 4Apr 19Oct 5
1987Apr 12Oct 3Apr 12Oct 3
1986Apr 22Oct 13Apr 22Oct 14
1985Apr 9Oct 1Apr 9Oct 1
1984Apr 19Sep 26Apr 5Sep 29
1983May 15Sep 21Apr 18Sep 23
1982Apr 22Oct 14Apr 22Oct 21
1981May 11Oct 2Apr 15Oct 19
1980May 9Oct 3May 8Oct 3
1979Apr 28Oct 5Apr 6Oct 10
1978May 3Oct 7May 2Oct 7
1977Apr 26Oct 9Apr 6Oct 12
1976May 8Oct 6May 7Oct 6
1975Apr 20Sep 25Apr 20Oct 16
1974Apr 17Sep 29Apr 15Oct 2
1973May 15Sep 18Apr 11Oct 29
1972Apr 25Sep 30Apr 8Oct 19
1971Apr 6Oct 31Apr 6Nov 6
1970Apr 23Oct 9Apr 4Oct 29
1969Apr 6Oct 14Mar 31Oct 14
1968Apr 25Oct 25Apr 5Nov 8
1967May 3Oct 11Apr 24Oct 28
1966May 9Oct 16May 1Oct 16
1965Apr 28Sep 24Mar 30Oct 24
1964Apr 9Oct 5Apr 8Oct 20
1963Apr 23Oct 29Mar 21Nov 1
1962Apr 15Oct 25Apr 15Oct 25
1961Apr 28Oct 1Apr 7Nov 2
1960Apr 18Oct 16Apr 10Oct 20
1959May 15Oct 9Apr 22Oct 14
1958no dataOct 1no dataOct 26
1956Apr 30Sep 30Apr 30Nov 8
1955Apr 7Oct 8Apr 7Oct 15
1954no dataOct 30no dataOct 31
1953Apr 27Sep 22Apr 20Oct 27
1952May 13no dataApr 15no data
1951May 7Sep 28Apr 19Sep 28

"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.