Last Frost Day

Frost history / Strontia Springs Dam, CO

Strontia Springs Dam, CO: frost dates by year

Last spring and first fall frost at NOAA station USC00058022, 1985 to 2025, measured from daily minimum temperatures.

Elevation 5,840 ft, 39.434, -105.121. Download the data (JSON), NOAA daily records

Summary at 32°F

Last spring frostFirst fall frost
MedianMay 21Sep 26
EarliestApr 30 (2012)Aug 12 (1999)
LatestJul 2 (1997)Oct 28 (2015)
Trend2.3 days earlier per decade5.6 days later per decade
Years with data3941

At 28°F (hard freeze) the median last spring date is May 8 and the median first fall date is Oct 7.

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 1419902000201020201985: May 141986: May 231987: May 281988: May 91989: May 51990: Jun 21991: May 121992: May 121993: May 101994: May 41995: May 261996: Jun 71997: Jul 21998: Jun 271999: Jun 282000: Jun 72001: Jun 152002: May 252003: May 202004: Jun 12005: May 122006: May 122007: Jun 92010: May 252011: May 202012: Apr 302013: May 212014: May 152015: May 172016: May 122017: May 242018: May 42019: May 252020: May 122021: May 122022: May 252023: May 12024: May 242025: May 22

First fall frost (32°F)

Jul 29Aug 13Aug 28Sep 12Sep 27Oct 12Oct 27Nov 1119902000201020201985: Sep 231986: Sep 261987: Oct 91988: Sep 191989: Sep 131990: Oct 71991: Sep 181992: Sep 261993: Sep 121994: Sep 151995: Sep 211996: Sep 191997: Sep 241998: Sep 191999: Aug 122000: Sep 232001: Sep 82002: Sep 222003: Sep 132004: Sep 222005: Oct 52006: Sep 172007: Oct 72008: Oct 72009: Sep 222010: Oct 92011: Oct 72012: Oct 52013: Sep 282014: Sep 122015: Oct 282016: Oct 52017: Oct 72018: Oct 72019: Oct 72020: Sep 92021: Oct 102022: Oct 122023: Oct 142024: Oct 252025: Oct 5

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 22Oct 5May 21Oct 14
2024May 24Oct 25May 23Oct 25
2023May 1Oct 14Apr 24Oct 14
2022May 25Oct 12May 3Oct 15
2021May 12Oct 10Apr 25Oct 13
2020May 12Sep 9May 10Oct 16
2019May 25Oct 7May 24Oct 10
2018May 4Oct 7Apr 26Oct 12
2017May 24Oct 7May 2Oct 10
2016May 12Oct 5May 3Oct 5
2015May 17Oct 28May 10Oct 28
2014May 15Sep 12May 14Oct 28
2013May 21Sep 28May 4Sep 28
2012Apr 30Oct 5Apr 28Oct 5
2011May 20Oct 7May 5Oct 7
2010May 25Oct 9May 8Oct 28
2009no dataSep 22no dataOct 2
2008no dataOct 7no dataOct 14
2007Jun 9Oct 7Apr 21Oct 8
2006May 12Sep 17May 12Sep 18
2005May 12Oct 5Apr 30Oct 6
2004Jun 1Sep 22May 1Oct 30
2003May 20Sep 13May 12Oct 14
2002May 25Sep 22May 24Sep 23
2001Jun 15Sep 8May 22Oct 5
2000Jun 7Sep 23Jun 5Oct 8
1999Jun 28Aug 12Jun 28Sep 12
1998Jun 27Sep 19Jun 20Sep 21
1997Jul 2Sep 24Jun 4Sep 29
1996Jun 7Sep 19Jun 2Sep 19
1995May 26Sep 21May 18Sep 21
1994May 4Sep 15May 2Sep 22
1993May 10Sep 12May 10Sep 13
1992May 12Sep 26Apr 25Sep 26
1991May 12Sep 18May 12Oct 4
1990Jun 2Oct 7May 10Oct 7
1989May 5Sep 13May 1Oct 16
1988May 9Sep 19May 3Sep 29
1987May 28Oct 9Apr 22Oct 10
1986May 23Sep 26Apr 18Oct 11
1985May 14Sep 23Apr 27Sep 29

"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.