Last Frost Day

Frost history / Rush 1N, CO

Rush 1N, CO: frost dates by year

Last spring and first fall frost at NOAA station USC00057287, 1959 to 2013, measured from daily minimum temperatures.

Elevation 6,054 ft, 38.861, -104.094. Download the data (JSON), NOAA daily records

Summary at 32°F

Last spring frostFirst fall frost
MedianMay 16Sep 28
EarliestApr 28 (2009)Sep 3 (1961)
LatestJun 18 (1976)Oct 27 (1963)
Trend2.1 days earlier per decade1.4 days later per decade
Years with data4848

At 28°F (hard freeze) the median last spring date is May 6 and the median first fall date is Oct 5.

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 291960197019801990200020101959: May 211960: May 201961: May 171962: May 21963: May 221964: May 291965: May 281966: May 141967: May 271968: May 221969: May 81970: Jun 11971: May 201976: Jun 181977: May 201978: May 191979: May 311980: May 191981: May 191982: May 61983: Jun 61984: May 101985: May 141986: May 181987: May 41989: May 51990: May 141991: May 131992: May 291993: May 101994: May 21995: May 231998: Jun 51999: May 112000: May 122001: May 202002: May 132003: May 212004: May 12005: May 122006: May 102007: Jun 82008: May 142009: Apr 282010: May 132011: May 162012: Apr 282013: May 5

First fall frost (32°F)

Aug 28Sep 12Sep 27Oct 12Oct 27Nov 111960197019801990200020101959: Sep 231960: Oct 141961: Sep 31962: Sep 91963: Oct 271964: Oct 31965: Sep 161966: Oct 11967: Oct 71968: Oct 31969: Oct 41970: Sep 231975: Sep 241976: Sep 271977: Sep 101978: Sep 211979: Sep 151980: Sep 231981: Oct 171982: Oct 61983: Sep 201984: Sep 251985: Sep 231986: Sep 271987: Oct 71988: Sep 191989: Sep 121990: Oct 31991: Sep 201992: Sep 261993: Sep 141994: Sep 201997: Oct 81998: Oct 41999: Sep 282000: Sep 232001: Oct 42002: Oct 72003: Oct 142004: Oct 102005: Oct 62006: Sep 162007: Oct 82008: Oct 72010: Oct 32011: Oct 102012: Oct 42013: Sep 28

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
2013May 5Sep 28May 4Oct 5
2012Apr 28Oct 4Apr 8Oct 7
2011May 16Oct 10May 5Oct 18
2010May 13Oct 3May 13Oct 26
2009Apr 28no dataApr 11no data
2008May 14Oct 7May 14Oct 22
2007Jun 8Oct 8Apr 15Oct 19
2006May 10Sep 16May 10Oct 18
2005May 12Oct 6May 3Oct 6
2004May 1Oct 10May 1Oct 14
2003May 21Oct 14Apr 9Oct 26
2002May 13Oct 7May 9Oct 13
2001May 20Oct 4Apr 23Oct 10
2000May 12Sep 23May 12Sep 24
1999May 11Sep 28May 11Sep 28
1998Jun 5Oct 4Apr 28Oct 4
1997no dataOct 8no dataOct 8
1995May 23no dataMay 17no data
1994May 2Sep 20May 1Sep 20
1993May 10Sep 14May 10Sep 14
1992May 29Sep 26Apr 20Sep 28
1991May 13Sep 20May 4Sep 23
1990May 14Oct 3May 10Oct 8
1989May 5Sep 12May 1Oct 6
1988no dataSep 19no dataSep 19
1987May 4Oct 7May 4Oct 10
1986May 18Sep 27Apr 27Sep 30
1985May 14Sep 23Apr 9Sep 29
1984May 10Sep 25May 10Sep 25
1983Jun 6Sep 20May 14Sep 20
1982May 6Oct 6May 6Oct 8
1981May 19Oct 17May 11Oct 18
1980May 19Sep 23May 16Oct 16
1979May 31Sep 15May 11Oct 10
1978May 19Sep 21May 18Sep 21
1977May 20Sep 10Apr 22Oct 1
1976Jun 18Sep 27May 8Sep 27
1975no dataSep 24no dataOct 9
1971May 20no dataMay 19no data
1970Jun 1Sep 23May 15Sep 26
1969May 8Oct 4Apr 28Oct 5
1968May 22Oct 3May 18Oct 5
1967May 27Oct 7May 16Oct 16
1966May 14Oct 1May 13Oct 4
1965May 28Sep 16May 10Sep 16
1964May 29Oct 3May 9Oct 3
1963May 22Oct 27Apr 30Oct 27
1962May 2Sep 9May 1Oct 16
1961May 17Sep 3Apr 28Sep 4
1960May 20Oct 14May 1Oct 29
1959May 21Sep 23May 6Sep 30

"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.