Last Frost Day

Frost history / Ridgway, CO

Ridgway, CO: frost dates by year

Last spring and first fall frost at NOAA station USC00057020, 1983 to 2025, measured from daily minimum temperatures.

Elevation 7,049 ft, 38.150, -107.758. Download the data (JSON), NOAA daily records

Summary at 32°F

Last spring frostFirst fall frost
MedianJun 13Sep 14
EarliestMay 27 (2024)Aug 13 (1985)
LatestJul 28 (1986)Oct 2 (2014)
Trend7.5 days earlier per decade4.5 days later per decade
Years with data4039

At 28°F (hard freeze) the median last spring date is May 26 and the median first fall date is Sep 23.

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)

May 15May 30Jun 14Jun 29Jul 14Jul 29Aug 1319902000201020201983: Jun 151984: Jun 231985: Jun 301986: Jul 281987: Jul 181988: Jun 141989: Jun 241990: Jul 141991: Jun 241992: Jun 171993: Jul 51994: Jun 111996: May 311997: Jul 41998: Jun 191999: Jun 122000: Jun 212001: Jun 162002: Jun 122003: Jun 252004: May 292006: May 312007: Jun 82008: Jun 132009: Jun 72010: May 302011: Jun 22013: Jun 32014: Jun 162015: May 302016: Jun 12017: May 302018: May 292019: Jun 252020: Jun 112021: Jun 12022: Jun 22023: Jun 242024: May 272025: May 27

First fall frost (32°F)

Jul 29Aug 13Aug 28Sep 12Sep 27Oct 1219902000201020201984: Sep 81985: Aug 131988: Sep 61989: Sep 11990: Aug 231991: Sep 141992: Aug 271993: Sep 141994: Sep 151995: Sep 191996: Sep 71997: Sep 241998: Sep 221999: Sep 92000: Sep 242001: Sep 92002: Aug 242003: Sep 102004: Aug 272005: Aug 312006: Sep 162007: Sep 172008: Sep 32009: Sep 202011: Sep 172012: Sep 152013: Sep 242014: Oct 22015: Sep 202016: Sep 112017: Sep 242018: Sep 152019: Sep 132020: Sep 122021: Sep 212022: Sep 162023: Sep 252024: Sep 182025: 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 21Sep 23
2024May 27Sep 18May 23Oct 22
2023Jun 24Sep 25May 9Oct 5
2022Jun 2Sep 16May 25Sep 16
2021Jun 1Sep 21May 25Sep 21
2020Jun 11Sep 12May 25Sep 28
2019Jun 25Sep 13May 26Sep 22
2018May 29Sep 15May 15Sep 27
2017May 30Sep 24May 22Sep 25
2016Jun 1Sep 11May 13Sep 17
2015May 30Sep 20May 12Oct 14
2014Jun 16Oct 2May 15Oct 3
2013Jun 3Sep 24Jun 1Sep 24
2012no dataSep 15no dataOct 7
2011Jun 2Sep 17May 30Sep 23
2010May 30no dataMay 29no data
2009Jun 7Sep 20Apr 29Sep 20
2008Jun 13Sep 3Jun 12Sep 23
2007Jun 8Sep 17Jun 7Sep 24
2006May 31Sep 16May 30Sep 16
2005no dataAug 31no dataSep 14
2004May 29Aug 27May 29Sep 14
2003Jun 25Sep 10May 20Sep 13
2002Jun 12Aug 24May 27Sep 23
2001Jun 16Sep 9Jun 15Sep 9
2000Jun 21Sep 24May 19Sep 25
1999Jun 12Sep 9Jun 7Sep 21
1998Jun 19Sep 22May 25Sep 27
1997Jul 4Sep 24May 26Oct 5
1996May 31Sep 7May 11Sep 19
1995no dataSep 19no dataSep 22
1994Jun 11Sep 15May 22Sep 15
1993Jul 5Sep 14Jun 24Sep 14
1992Jun 17Aug 27May 11Sep 26
1991Jun 24Sep 14Jun 2Sep 16
1990Jul 14Aug 23Jun 21Sep 24
1989Jun 24Sep 1Jun 4Sep 9
1988Jun 14Sep 6Jun 2Sep 14
1987Jul 18no dataJun 3no data
1986Jul 28no dataMay 28no data
1985Jun 30Aug 13Jun 30Sep 8
1984Jun 23Sep 8May 19Sep 28
1983Jun 15no dataJun 14no data

"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.