Last Frost Day

Frost history / Denver-Stapleton, CO

Denver-Stapleton, CO: frost dates by year

Last spring and first fall frost at NOAA station USW00023062, 1951 to 2024, measured from daily minimum temperatures.

Elevation 5,286 ft, 39.763, -104.869. Download the data (JSON), NOAA daily records

Summary at 32°F

Last spring frostFirst fall frost
MedianMay 3Oct 9
EarliestApr 5 (1977)Sep 8 (1962)
LatestJun 2 (1951)Oct 31 (2024)
Trend0.6 days later per decadelittle change (less than half a day per decade)
Years with data7374

At 28°F (hard freeze) the median last spring date is Apr 23 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 31Apr 15Apr 30May 15May 30Jun 1419601970198019902000201020201951: Jun 21952: Apr 231953: May 131954: May 31955: Apr 281956: Apr 241957: May 171958: Apr 301959: Apr 221960: May 11961: May 131962: Apr 131963: Apr 241964: May 121965: May 91966: May 131967: May 141968: May 191969: Apr 281970: May 151971: May 191972: May 31973: May 21974: Apr 161975: May 11976: Apr 181977: Apr 51978: May 71979: May 111980: Apr 141981: Apr 51982: May 61983: May 181984: Apr 301985: Apr 271986: Apr 191987: Apr 211988: May 31989: May 11990: May 101991: May 11992: Apr 251993: May 21994: Apr 301995: May 11996: Apr 291997: May 31998: Apr 291999: May 62000: May 132001: May 212002: May 242003: May 122004: May 132005: May 122006: May 112007: Apr 152008: May 142010: May 142011: May 62012: Apr 282013: May 42014: May 152015: May 112016: May 32017: May 212018: Apr 262019: May 222020: Apr 192021: May 122022: May 222023: Apr 242024: Apr 28

First fall frost (32°F)

Aug 28Sep 12Sep 27Oct 12Oct 27Nov 1119601970198019902000201020201951: Sep 211952: Oct 51953: Oct 41954: Oct 141955: Oct 231956: Oct 201957: Oct 241958: Oct 221959: Sep 291960: Oct 191961: Sep 251962: Sep 81963: Oct 271964: Oct 41965: Sep 161966: Oct 141967: Oct 161968: Oct 91969: Oct 41970: Oct 71971: Sep 171972: Oct 231973: Oct 111974: Oct 301975: Sep 201976: Oct 71977: Oct 21978: Sep 211979: Oct 221980: Oct 171981: Oct 221982: Oct 71983: Sep 201984: Sep 251985: Sep 231986: Sep 271987: Oct 91988: Oct 231989: Oct 161990: Oct 71991: Oct 51992: Oct 71993: Sep 141994: Sep 221995: Sep 201996: Sep 251997: Oct 131998: Oct 171999: Sep 282000: Sep 242001: Oct 52002: Oct 122003: Oct 142004: Oct 142005: Oct 72006: Oct 182007: Oct 162008: Oct 122009: Oct 22010: Oct 92011: Oct 182012: Oct 52013: Oct 52014: Sep 142015: Oct 282016: Oct 202017: Oct 92018: Oct 102019: Oct 102020: Sep 92021: Oct 152022: Oct 172023: Oct 132024: Oct 31

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
2024Apr 28Oct 31Apr 20Oct 31
2023Apr 24Oct 13Apr 23Oct 27
2022May 22Oct 17Apr 16Nov 4
2021May 12Oct 15Apr 22Oct 15
2020Apr 19Sep 9Apr 18Oct 17
2019May 22Oct 10Apr 13Oct 10
2018Apr 26Oct 10Apr 18Oct 14
2017May 21Oct 9Apr 30Oct 10
2016May 3Oct 20May 3Nov 18
2015May 11Oct 28May 11Nov 7
2014May 15Sep 14Apr 15Nov 11
2013May 4Oct 5May 3Oct 5
2012Apr 28Oct 5Mar 22Oct 7
2011May 6Oct 18Apr 5Oct 19
2010May 14Oct 9Apr 9Oct 29
2009no dataOct 2no dataOct 9
2008May 14Oct 12May 4Oct 23
2007Apr 15Oct 16Apr 15Oct 22
2006May 11Oct 18Apr 27Oct 18
2005May 12Oct 7May 1Oct 24
2004May 13Oct 14May 1Oct 31
2003May 12Oct 14May 12Oct 30
2002May 24Oct 12Apr 22Oct 17
2001May 21Oct 5Apr 23Oct 6
2000May 13Sep 24May 13Nov 4
1999May 6Sep 28May 6Sep 29
1998Apr 29Oct 17Apr 17Oct 18
1997May 3Oct 13May 3Oct 24
1996Apr 29Sep 25Apr 29Sep 27
1995May 1Sep 20Apr 26Sep 21
1994Apr 30Sep 22Apr 27Oct 25
1993May 2Sep 14Apr 4Oct 9
1992Apr 25Oct 7Apr 1Oct 7
1991May 1Oct 5Apr 13Oct 28
1990May 10Oct 7Apr 6Oct 9
1989May 1Oct 16May 1Oct 18
1988May 3Oct 23May 3Oct 23
1987Apr 21Oct 9Apr 14Oct 10
1986Apr 19Sep 27Apr 15Oct 11
1985Apr 27Sep 23Apr 8Sep 28
1984Apr 30Sep 25Apr 28Oct 15
1983May 18Sep 20May 18Sep 20
1982May 6Oct 7Apr 22Oct 11
1981Apr 5Oct 22Apr 5Oct 22
1980Apr 14Oct 17Apr 13Oct 23
1979May 11Oct 22Apr 12Oct 31
1978May 7Sep 21May 7Oct 23
1977Apr 5Oct 2Apr 4Oct 10
1976Apr 18Oct 7Apr 3Oct 16
1975May 1Sep 20Apr 18Oct 23
1974Apr 16Oct 30Apr 15Oct 31
1973May 2Oct 11Apr 16Nov 2
1972May 3Oct 23May 2Oct 25
1971May 19Sep 17Apr 6Sep 18
1970May 15Oct 7May 1Oct 7
1969Apr 28Oct 4Apr 28Oct 5
1968May 19Oct 9May 8Oct 17
1967May 14Oct 16May 3Oct 24
1966May 13Oct 14May 12Oct 14
1965May 9Sep 16Apr 14Nov 4
1964May 12Oct 4May 4Oct 18
1963Apr 24Oct 27Apr 23Oct 27
1962Apr 13Sep 8Apr 12Oct 24
1961May 13Sep 25Apr 25Oct 23
1960May 1Oct 19Apr 30Oct 29
1959Apr 22Sep 29Apr 21Oct 30
1958Apr 30Oct 22Apr 29Oct 31
1957May 17Oct 24Apr 26Oct 25
1956Apr 24Oct 20Apr 9Oct 25
1955Apr 28Oct 23Apr 28Oct 23
1954May 3Oct 14May 2Oct 26
1953May 13Oct 4May 13Nov 7
1952Apr 23Oct 5Apr 10Oct 7
1951Jun 2Sep 21Apr 21Oct 21

"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.