Last Frost Day

Frost history / Manassa, CO

Manassa, CO: frost dates by year

Last spring and first fall frost at NOAA station USC00055322, 1952 to 2025, measured from daily minimum temperatures.

Elevation 7,695 ft, 37.171, -105.940. Download the data (JSON), NOAA daily records

Summary at 32°F

Last spring frostFirst fall frost
MedianJun 6Sep 14
EarliestMay 3 (2009)Aug 6 (1976)
LatestJul 8 (1955)Oct 5 (1997)
Trend2.5 days earlier per decade3.6 days later per decade
Years with data5350

At 28°F (hard freeze) the median last spring date is May 27 and the median first fall date is Sep 21.

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 29Jul 1419601970198019902000201020201952: Jun 281953: Jun 41954: Jun 121955: Jul 81956: May 171957: Jun 221958: Jun 101960: May 261962: Jun 161963: Jun 91971: Jun 71972: May 271973: Jun 61974: Jun 101975: Jun 261976: Jun 241977: May 281978: Jun 61979: Jun 201980: Jun 21981: Jun 161982: Jun 211983: Jun 151984: Jun 161985: Jun 271986: May 291988: Jun 11990: Jun 171991: May 171992: Jun 171994: May 211995: Jun 111996: May 291997: May 271998: Jun 181999: Jun 62000: May 202001: Jun 152002: May 262003: May 122005: Jun 42008: Jun 132009: May 32010: May 262011: May 312012: May 292013: Jun 12014: Jun 92020: Jun 102021: Jun 12022: May 312024: May 262025: May 27

First fall frost (32°F)

Jul 29Aug 13Aug 28Sep 12Sep 27Oct 1219601970198019902000201020201952: Aug 301953: Aug 71954: Sep 191955: Aug 311956: Aug 291957: Sep 21958: Sep 151960: Aug 181969: Sep 21970: Sep 71971: Sep 41972: Sep 161973: Sep 31974: Sep 31976: Aug 61979: Aug 211980: Aug 211981: Sep 181982: Sep 191983: Sep 211984: Sep 281985: Sep 61986: Sep 111987: Aug 291988: Sep 151990: Oct 41991: Sep 141992: Aug 271993: Sep 141994: Sep 151995: Sep 221996: Sep 191997: Oct 51998: Sep 271999: Sep 162000: Sep 242001: Sep 92002: Sep 202003: Sep 112007: Sep 252008: Sep 132009: Sep 222010: Sep 112011: Sep 182012: Sep 152013: Sep 242014: Sep 302020: Sep 72024: Sep 232025: Sep 14

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 27Sep 14May 20Sep 24
2024May 26Sep 23May 22Oct 22
2022May 31no dataMay 25no data
2021Jun 1no dataJun 1no data
2020Jun 10Sep 7Jun 9Sep 7
2014Jun 9Sep 30May 14Oct 3
2013Jun 1Sep 24May 11Sep 28
2012May 29Sep 15May 28Oct 7
2011May 31Sep 18May 31Oct 10
2010May 26Sep 11May 25Sep 11
2009May 3Sep 22Apr 30Sep 22
2008Jun 13Sep 13Jun 13Oct 6
2007no dataSep 25no dataSep 25
2005Jun 4no dataMay 13no data
2003May 12Sep 11May 11Oct 13
2002May 26Sep 20May 23Oct 4
2001Jun 15Sep 9Apr 23Sep 9
2000May 20Sep 24May 18Sep 25
1999Jun 6Sep 16May 12Sep 22
1998Jun 18Sep 27May 23Sep 27
1997May 27Oct 5May 27Oct 9
1996May 29Sep 19Apr 30Sep 19
1995Jun 11Sep 22May 10Sep 23
1994May 21Sep 15May 4Sep 15
1993no dataSep 14no dataSep 14
1992Jun 17Aug 27Apr 26Sep 26
1991May 17Sep 14May 13Sep 16
1990Jun 17Oct 4Jun 2Oct 9
1988Jun 1Sep 15May 31Sep 19
1987no dataAug 29no dataSep 9
1986May 29Sep 11May 29Sep 11
1985Jun 27Sep 6Jun 27Sep 13
1984Jun 16Sep 28Jun 10Oct 6
1983Jun 15Sep 21Jun 14Sep 21
1982Jun 21Sep 19May 21Oct 2
1981Jun 16Sep 18Jun 16Sep 27
1980Jun 2Aug 21May 30Sep 18
1979Jun 20Aug 21Jun 10Sep 16
1978Jun 6no dataMay 29no data
1977May 28no dataMay 27no data
1976Jun 24Aug 6Jun 15Sep 23
1975Jun 26no dataJun 11no data
1974Jun 10Sep 3Jun 9Sep 27
1973Jun 6Sep 3Jun 5Sep 3
1972May 27Sep 16May 27Sep 30
1971Jun 7Sep 4Jun 5Sep 5
1970no dataSep 7no dataSep 7
1969no dataSep 2no dataOct 5
1963Jun 9no dataMay 12no data
1962Jun 16no dataMay 22no data
1960May 26Aug 18May 26Sep 16
1958Jun 10Sep 15May 17Sep 15
1957Jun 22Sep 2Jun 17Sep 12
1956May 17Aug 29May 16Sep 1
1955Jul 8Aug 31Jun 10Sep 21
1954Jun 12Sep 19Jun 7Sep 19
1953Jun 4Aug 7Jun 4Sep 4
1952Jun 28Aug 30May 17Sep 14

"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.