Last Frost Day

Frost history / Byers 5 Ene, CO

Byers 5 Ene, CO: frost dates by year

Last spring and first fall frost at NOAA station USC00051179, 1951 to 2019, measured from daily minimum temperatures.

Elevation 5,101 ft, 39.741, -104.127. Download the data (JSON), NOAA daily records

Summary at 32°F

Last spring frostFirst fall frost
MedianMay 13Sep 28
EarliestApr 23 (1987)Sep 3 (1973)
LatestJun 11 (1975)Oct 27 (1963)
Trendlittle change (less than half a day per decade)little change (less than half a day per decade)
Years with data6265

At 28°F (hard freeze) the median last spring date is May 1 and the median first fall date is Oct 6.

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)

Apr 15Apr 30May 15May 30Jun 14Jun 291960197019801990200020101951: Jun 31952: May 101953: May 131954: Jun 31955: May 171956: May 151957: May 161958: Apr 301959: Apr 281960: May 191962: May 151963: May 211964: May 121965: May 101966: May 131967: May 151968: May 191969: Apr 281970: May 151971: May 231972: May 71973: May 141974: May 221975: Jun 111976: May 171977: Apr 241978: May 131979: May 111980: May 131981: May 121982: May 61983: May 181984: May 81985: Apr 271986: May 101987: Apr 231988: May 41989: May 61990: May 141991: May 131992: Apr 261993: Jun 71994: Apr 301995: May 141996: May 31997: May 121998: Apr 291999: May 122000: May 132001: May 212002: May 232003: May 112004: May 132005: May 132006: May 162007: Jun 82008: May 142009: May 142010: May 132011: May 122012: May 282019: May 23

First fall frost (32°F)

Aug 28Sep 12Sep 27Oct 12Oct 27Nov 111960197019801990200020101951: Sep 271952: Oct 51953: Oct 41954: Sep 291955: Oct 71956: Oct 141957: Sep 221958: Sep 301959: Sep 281960: Oct 151961: Sep 241962: Sep 91963: Oct 271964: Sep 271965: Sep 161966: Oct 11967: Sep 271968: Sep 161969: Oct 31970: Sep 121971: Sep 171972: Sep 301973: Sep 31974: Sep 121975: Sep 201976: Sep 281977: Sep 241978: Sep 191979: Oct 41980: Oct 101981: Oct 171982: Oct 61983: Sep 201984: Sep 251985: Sep 231986: Sep 271987: Sep 291988: Oct 201989: Oct 21990: Oct 81991: Sep 191992: Sep 261993: Sep 131994: Sep 221995: Sep 211996: Sep 271997: Sep 281998: Oct 61999: Sep 282001: Oct 52002: Oct 42003: Sep 142004: Oct 142005: Oct 52006: Sep 182007: Oct 82008: Sep 232009: Oct 12010: Oct 132011: Oct 132012: Oct 42014: Sep 122015: Oct 172016: Sep 102018: Oct 10

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