Last Frost Day

Frost history / Ames 8 Wsw, IA

Ames 8 Wsw, IA: frost dates by year

Last spring and first fall frost at NOAA station USC00130200, 1965 to 2025, measured from daily minimum temperatures.

Elevation 1,099 ft, 42.021, -93.774. Download the data (JSON), NOAA daily records

Summary at 32°F

Last spring frostFirst fall frost
MedianApr 24Oct 8
EarliestApr 5 (1987)Sep 19 (1991)
LatestMay 13 (1997)Nov 3 (1998)
Trend1.5 days earlier per decade2.9 days later per decade
Years with data6161

At 28°F (hard freeze) the median last spring date is Apr 12 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 301970198019902000201020201965: Apr 191966: May 101967: May 31968: Apr 251969: May 121970: May 21971: Apr 151972: Apr 251973: May 21974: May 61975: Apr 221976: May 31977: Apr 61978: May 21979: May 121980: May 81981: May 111982: Apr 221983: Apr 201984: Apr 221985: Apr 91986: May 21987: Apr 51988: Apr 241989: May 61990: May 11991: Apr 101992: Apr 221993: Apr 201994: May 11995: Apr 271996: May 61997: May 131998: Apr 171999: Apr 182000: Apr 122001: Apr 182002: Apr 92003: Apr 102004: May 32005: May 42006: Apr 92007: Apr 142008: Apr 292009: Apr 142010: Apr 92011: May 42012: Apr 122013: May 42014: Apr 182015: Apr 232016: Apr 122017: Apr 282018: Apr 202019: May 32020: May 92021: Apr 222022: Apr 262023: Apr 242024: Apr 212025: Apr 8

First fall frost (32°F)

Sep 12Sep 27Oct 12Oct 27Nov 111970198019902000201020201965: Oct 121966: Oct 11967: Sep 291968: Oct 41969: Oct 141970: Oct 101971: Oct 101972: Sep 301973: Oct 291974: Sep 221975: Oct 21976: Oct 61977: Oct 111978: Oct 81979: Oct 51980: Sep 261981: Oct 21982: Oct 161983: Sep 231984: Sep 261985: Oct 11986: Oct 61987: Oct 31988: Oct 41989: Sep 231990: Oct 101991: Sep 191992: Oct 171993: Oct 91994: Oct 251995: Sep 221996: Oct 31997: Oct 141998: Nov 31999: Oct 42000: Oct 62001: Oct 62002: Oct 72003: Sep 292004: Oct 22005: Oct 72006: Oct 122007: Oct 232008: Oct 212009: Oct 72010: Oct 292011: Oct 202012: Oct 52013: Oct 192014: Oct 312015: Oct 182016: Oct 132017: Oct 272018: Oct 142019: Oct 122020: Oct 162021: Oct 232022: Oct 82023: Oct 282024: Oct 152025: Nov 2

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
2025Apr 8Nov 2Apr 8Nov 9
2024Apr 21Oct 15Mar 28Nov 23
2023Apr 24Oct 28Apr 23Oct 28
2022Apr 26Oct 8Apr 26Oct 14
2021Apr 22Oct 23Apr 22Nov 1
2020May 9Oct 16Apr 17Oct 19
2019May 3Oct 12Apr 13Oct 12
2018Apr 20Oct 14Apr 19Oct 21
2017Apr 28Oct 27Mar 23Oct 29
2016Apr 12Oct 13Apr 12Nov 12
2015Apr 23Oct 18Apr 4Nov 20
2014Apr 18Oct 31Apr 18Oct 31
2013May 4Oct 19Apr 24Oct 23
2012Apr 12Oct 5Apr 11Oct 6
2011May 4Oct 20May 3Oct 21
2010Apr 9Oct 29Mar 26Oct 29
2009Apr 14Oct 7Apr 7Oct 10
2008Apr 29Oct 21Apr 14Oct 28
2007Apr 14Oct 23Apr 13Nov 1
2006Apr 9Oct 12Apr 8Oct 12
2005May 4Oct 7Mar 23Oct 28
2004May 3Oct 2Apr 13Nov 3
2003Apr 10Sep 29Apr 10Oct 26
2002Apr 9Oct 7Apr 7Oct 13
2001Apr 18Oct 6Apr 17Oct 17
2000Apr 12Oct 6Apr 12Oct 6
1999Apr 18Oct 4Mar 27Oct 4
1998Apr 17Nov 3Mar 24Nov 4
1997May 13Oct 14Apr 17Oct 22
1996May 6Oct 3Apr 23Oct 30
1995Apr 27Sep 22Apr 5Oct 22
1994May 1Oct 25Apr 7Oct 26
1993Apr 20Oct 9Apr 5Oct 10
1992Apr 22Oct 17Apr 13Oct 17
1991Apr 10Sep 19Mar 30Oct 7
1990May 1Oct 10Apr 18Oct 10
1989May 6Sep 23Apr 13Oct 19
1988Apr 24Oct 4Apr 24Oct 22
1987Apr 5Oct 3Apr 4Oct 3
1986May 2Oct 6Apr 15Oct 14
1985Apr 9Oct 1Apr 9Oct 1
1984Apr 22Sep 26Apr 1Oct 23
1983Apr 20Sep 23Apr 19Oct 13
1982Apr 22Oct 16Apr 11Oct 21
1981May 11Oct 2Apr 6Oct 19
1980May 8Sep 26Apr 14Oct 12
1979May 12Oct 5Apr 10Oct 13
1978May 2Oct 8Mar 26Oct 19
1977Apr 6Oct 11Apr 6Oct 16
1976May 3Oct 6Apr 12Oct 8
1975Apr 22Oct 2Apr 12Oct 25
1974May 6Sep 22Apr 8Oct 2
1973May 2Oct 29Apr 13Oct 30
1972Apr 25Sep 30Apr 8Oct 15
1971Apr 15Oct 10Apr 14Oct 31
1970May 2Oct 10May 2Nov 14
1969May 12Oct 14Apr 1Oct 14
1968Apr 25Oct 4Apr 25Oct 4
1967May 3Sep 29May 2Oct 11
1966May 10Oct 1May 10Oct 17
1965Apr 19Oct 12Mar 30Oct 24

"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.