Last Frost Day

Frost history / Burlington, CO

Burlington, CO: frost dates by year

Last spring and first fall frost at NOAA station USC00051121, 1951 to 2025, measured from daily minimum temperatures.

Elevation 4,162 ft, 39.306, -102.261. Download the data (JSON), NOAA daily records

Summary at 32°F

Last spring frostFirst fall frost
MedianMay 5Oct 9
EarliestApr 16 (2012)Sep 6 (1956)
LatestJun 2 (1951)Oct 31 (2024)
Trendlittle change (less than half a day per decade)1.8 days later per decade
Years with data6363

At 28°F (hard freeze) the median last spring date is Apr 22 and the median first fall date is Oct 20.

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 30Jun 1419601970198019902000201020201951: Jun 21952: May 111953: May 141954: May 41955: Apr 281956: Apr 301957: Apr 201958: Apr 291959: Apr 291960: May 11961: Apr 281964: Apr 171965: May 91966: May 121967: May 31968: May 191969: Apr 271970: May 151971: May 111974: Apr 221979: May 131980: May 121981: May 101982: May 61983: May 161984: May 81985: May 151986: Apr 271987: Apr 211988: May 41990: May 91991: May 41992: May 261993: May 21994: May 21995: May 181996: May 11997: May 91998: Apr 281999: May 72000: May 132001: May 252002: May 252003: Apr 192004: May 152005: May 122009: Apr 282010: May 132011: May 32012: Apr 162013: May 52014: May 142015: May 112016: May 32017: May 12018: Apr 262019: May 222020: May 122021: Apr 252022: May 222023: Apr 242024: May 42025: Apr 20

First fall frost (32°F)

Aug 28Sep 12Sep 27Oct 12Oct 27Nov 1119601970198019902000201020201951: Sep 161952: Oct 51953: Oct 41954: Oct 151955: Oct 71956: Sep 61957: Sep 221958: Oct 11959: Sep 291960: Oct 191961: Sep 251963: Oct 281964: Oct 181965: Sep 161966: Oct 131967: Oct 71968: Oct 161969: Oct 41970: Sep 111971: Sep 181973: Oct 101976: Sep 281978: Oct 51979: Oct 301980: Oct 171981: Oct 191982: Oct 111983: Sep 201984: Sep 251985: Sep 281986: Oct 111987: Oct 101988: Oct 231991: Oct 41992: Oct 81993: Sep 141994: Oct 241995: Sep 211996: Oct 181997: Oct 91998: Oct 62000: Sep 242001: Oct 62002: Oct 132003: Oct 142004: Oct 142005: Oct 72009: Oct 22010: Oct 262011: Oct 182012: Oct 42014: Oct 312015: Oct 282016: Oct 72017: Oct 102018: Oct 102019: Oct 102020: Sep 92021: Oct 142022: Oct 172023: Oct 142024: Oct 312025: Oct 19

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 20Oct 19Apr 19Oct 29
2024May 4Oct 31Apr 21Nov 5
2023Apr 24Oct 14Apr 23Oct 14
2022May 22Oct 17Apr 25Oct 28
2021Apr 25Oct 14Apr 23Nov 1
2020May 12Sep 9Apr 18Oct 23
2019May 22Oct 10Apr 15Oct 10
2018Apr 26Oct 10Apr 25Oct 11
2017May 1Oct 10Apr 26Oct 10
2016May 3Oct 7May 2Nov 11
2015May 11Oct 28Apr 4Nov 7
2014May 14Oct 31Apr 15Oct 31
2013May 5no dataMay 4no data
2012Apr 16Oct 4Mar 9Oct 25
2011May 3Oct 18Apr 16Oct 27
2010May 13Oct 26May 13Oct 28
2009Apr 28Oct 2Apr 11Oct 9
2005May 12Oct 7May 2Oct 7
2004May 15Oct 14Apr 13Oct 14
2003Apr 19Oct 14Apr 9Oct 26
2002May 25Oct 13May 9Oct 15
2001May 25Oct 6Apr 18Oct 16
2000May 13Sep 24Apr 17Oct 6
1999May 7no dataApr 18no data
1998Apr 28Oct 6Apr 28Oct 21
1997May 9Oct 9May 3Oct 25
1996May 1Oct 18Apr 30Oct 18
1995May 18Sep 21Apr 19Oct 20
1994May 2Oct 24Apr 28Oct 25
1993May 2Sep 14Apr 21Oct 9
1992May 26Oct 8Apr 2Oct 8
1991May 4Oct 4Apr 13Oct 24
1990May 9no dataApr 11no data
1988May 4Oct 23Apr 26Oct 28
1987Apr 21Oct 10Apr 6Oct 19
1986Apr 27Oct 11Apr 16Oct 11
1985May 15Sep 28Apr 8Sep 28
1984May 8Sep 25Apr 30Sep 28
1983May 16Sep 20Apr 15Sep 20
1982May 6Oct 11Apr 23Oct 19
1981May 10Oct 19Apr 5Oct 23
1980May 12Oct 17Apr 26Oct 24
1979May 13Oct 30May 13Oct 31
1978no dataOct 5no dataOct 5
1976no dataSep 28no dataOct 18
1974Apr 22no dataApr 16no data
1973no dataOct 10no dataNov 1
1971May 11Sep 18Apr 6Oct 28
1970May 15Sep 11May 2Oct 7
1969Apr 27Oct 4Apr 27Oct 11
1968May 19Oct 16Apr 22Oct 17
1967May 3Oct 7May 2Oct 26
1966May 12Oct 13Apr 28Oct 14
1965May 9Sep 16Mar 29Nov 17
1964Apr 17Oct 18Apr 12Oct 18
1963no dataOct 28no dataNov 1
1961Apr 28Sep 25Apr 28Oct 19
1960May 1Oct 19Apr 30Oct 30
1959Apr 29Sep 29Apr 29Oct 17
1958Apr 29Oct 1Apr 29Oct 1
1957Apr 20Sep 22Apr 14Oct 24
1956Apr 30Sep 6Apr 30Oct 25
1955Apr 28Oct 7Apr 28Oct 23
1954May 4Oct 15May 3Oct 22
1953May 14Oct 4May 14Oct 26
1952May 11Oct 5Apr 14Oct 6
1951Jun 2Sep 16Apr 22Oct 17

"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.