Last Frost Day

Frost history / Greeley Unc, CO

Greeley Unc, CO: frost dates by year

Last spring and first fall frost at NOAA station USC00053553, 1967 to 2025, measured from daily minimum temperatures.

Elevation 4,715 ft, 40.402, -104.699. Download the data (JSON), NOAA daily records

Summary at 32°F

Last spring frostFirst fall frost
MedianMay 2Oct 6
EarliestApr 9 (2012)Sep 9 (2020)
LatestMay 22 (2019)Oct 28 (2015)
Trendlittle change (less than half a day per decade)2.0 days later per decade
Years with data5859

At 28°F (hard freeze) the median last spring date is Apr 19 and the median first fall date is Oct 16.

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 301970198019902000201020201968: May 171969: Apr 281970: May 151971: May 191972: May 31973: May 11974: Apr 161975: May 11976: May 11977: Apr 211978: May 71979: May 111980: May 131981: May 101982: Apr 281983: May 171984: Apr 301985: Apr 271986: Apr 191987: Apr 221988: May 41989: May 11990: May 101991: May 31992: Apr 251993: May 21994: Apr 301995: Apr 271996: Apr 291997: May 31998: Apr 201999: Apr 252000: May 132001: May 212002: May 92003: May 112004: May 12005: May 122006: May 112007: Apr 262008: May 112009: Apr 272010: May 132011: May 52012: Apr 92013: May 52014: May 132015: May 112016: May 22017: May 192018: Apr 252019: May 222020: Apr 182021: Apr 252022: Apr 262023: Apr 232024: Apr 212025: May 20

First fall frost (32°F)

Aug 28Sep 12Sep 27Oct 12Oct 27Nov 111970198019902000201020201967: Oct 161968: Oct 91969: Oct 41970: Sep 261971: Sep 171972: Oct 231973: Oct 111974: Sep 281975: Sep 201976: Sep 291977: Oct 21978: Sep 211979: Oct 41980: Oct 111981: Oct 171982: Oct 61983: Sep 201984: Sep 251985: Sep 231986: Oct 41987: Oct 71988: Oct 231989: Sep 121990: Oct 71991: Oct 51992: Oct 81993: Sep 141994: Sep 221995: Sep 211996: Sep 271997: Oct 91998: Oct 61999: Sep 282000: Sep 232001: Oct 62002: Oct 72003: Oct 12004: Oct 162005: Oct 72006: Oct 172007: Oct 82008: Oct 132009: Oct 32010: Oct 192011: Oct 192012: Oct 52013: Oct 52014: Sep 132015: Oct 282016: Oct 202017: Oct 92018: Oct 102019: Oct 72020: Sep 92021: Oct 162022: Oct 242023: Oct 142024: Oct 252025: 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
2025May 20Oct 19Apr 20Oct 29
2024Apr 21Oct 25Apr 21Nov 1
2023Apr 23Oct 14Apr 23Oct 27
2022Apr 26Oct 24Apr 18Oct 25
2021Apr 25Oct 16Apr 22Nov 11
2020Apr 18Sep 9Apr 17Oct 16
2019May 22Oct 7Apr 14Oct 7
2018Apr 25Oct 10Apr 19Oct 14
2017May 19Oct 9Apr 26Oct 10
2016May 2Oct 20May 2Nov 17
2015May 11Oct 28May 10Nov 7
2014May 13Sep 13Apr 15Nov 4
2013May 5Oct 5May 3Oct 16
2012Apr 9Oct 5Mar 21Oct 7
2011May 5Oct 19May 3Oct 19
2010May 13Oct 19May 8Oct 28
2009Apr 27Oct 3Apr 7Oct 3
2008May 11Oct 13May 3Oct 27
2007Apr 26Oct 8Apr 14Oct 22
2006May 11Oct 17Apr 26Oct 18
2005May 12Oct 7Apr 30Oct 24
2004May 1Oct 16Apr 12Oct 31
2003May 11Oct 1Apr 9Oct 30
2002May 9Oct 7Apr 19Oct 13
2001May 21Oct 6Apr 23Oct 6
2000May 13Sep 23Apr 16Sep 25
1999Apr 25Sep 28Apr 17Sep 29
1998Apr 20Oct 6Apr 17Oct 18
1997May 3Oct 9Apr 14Oct 13
1996Apr 29Sep 27Apr 29Sep 27
1995Apr 27Sep 21Apr 12Sep 22
1994Apr 30Sep 22Apr 28Oct 25
1993May 2Sep 14Apr 20Oct 9
1992Apr 25Oct 8Apr 1Oct 8
1991May 3Oct 5Apr 13Oct 6
1990May 10Oct 7Apr 6Oct 9
1989May 1Sep 12May 1Oct 19
1988May 4Oct 23Apr 23Oct 28
1987Apr 22Oct 7Apr 21Oct 10
1986Apr 19Oct 4Apr 15Oct 11
1985Apr 27Sep 23Apr 8Sep 26
1984Apr 30Sep 25Apr 28Sep 28
1983May 17Sep 20May 12Sep 20
1982Apr 28Oct 6Apr 23Oct 11
1981May 10Oct 17Apr 5Oct 19
1980May 13Oct 11Apr 14Oct 17
1979May 11Oct 4May 10Oct 22
1978May 7Sep 21May 7Oct 14
1977Apr 21Oct 2Apr 6Oct 9
1976May 1Sep 29Apr 4Oct 7
1975May 1Sep 20Apr 18Oct 14
1974Apr 16Sep 28Apr 16Oct 31
1973May 1Oct 11Apr 16Oct 27
1972May 3Oct 23Apr 4Oct 25
1971May 19Sep 17Apr 9Sep 19
1970May 15Sep 26May 1Oct 7
1969Apr 28Oct 4Apr 28Oct 5
1968May 17Oct 9May 17Oct 18
1967no dataOct 16no dataOct 16

"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.