Frost history / Collbran 1WSW, CO
Collbran 1WSW, CO: frost dates by year
Last spring and first fall frost at NOAA station USC00051743, 2000 to 2023, measured from daily minimum temperatures.
Elevation 6,009 ft, 39.237, -107.980. Download the data (JSON), NOAA daily records
Summary at 32°F
| Last spring frost | First fall frost | |
|---|---|---|
| Median | May 25 | Sep 25 |
| Earliest | Apr 27 (2018) | Sep 7 (2010) |
| Latest | Jun 14 (2001) | Oct 24 (2015) |
| Trend | 7.3 days earlier per decade | 6.8 days later per decade |
| Years with data | 23 | 24 |
At 28°F (hard freeze) the median last spring date is May 8 and the median first fall date is Oct 11.
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)
First fall frost (32°F)
Dots are single years. The gray line is the median, the green line the fitted trend.
Year by year
| Year | Last spring 32°F | First fall 32°F | Last spring 28°F | First fall 28°F |
|---|---|---|---|---|
| 2023 | Apr 29 | Oct 8 | Apr 26 | Oct 14 |
| 2022 | May 25 | Oct 14 | May 21 | Oct 24 |
| 2021 | May 24 | Oct 10 | May 12 | Oct 11 |
| 2020 | May 21 | Sep 9 | May 8 | Oct 12 |
| 2019 | May 25 | Sep 22 | May 2 | Oct 3 |
| 2018 | Apr 27 | Oct 12 | Apr 25 | Oct 15 |
| 2017 | May 21 | Sep 25 | Apr 30 | Oct 3 |
| 2016 | May 26 | Oct 4 | May 12 | Oct 4 |
| 2015 | May 20 | Oct 24 | May 11 | Oct 24 |
| 2014 | May 15 | Sep 12 | May 14 | Oct 13 |
| 2013 | Jun 1 | Sep 20 | May 3 | Sep 28 |
| 2012 | May 27 | Oct 4 | Apr 30 | Oct 6 |
| 2011 | May 31 | Oct 7 | May 5 | Oct 7 |
| 2010 | May 30 | Sep 7 | May 25 | Oct 14 |
| 2009 | May 9 | Sep 22 | Apr 27 | Oct 1 |
| 2008 | May 23 | Oct 7 | May 13 | Oct 12 |
| 2007 | Jun 8 | Sep 25 | Jun 8 | Sep 25 |
| 2006 | May 30 | Sep 17 | May 10 | Sep 17 |
| 2005 | May 14 | Oct 5 | May 1 | Oct 31 |
| 2004 | May 30 | Sep 15 | Apr 11 | Oct 14 |
| 2003 | May 20 | Sep 18 | May 11 | Oct 11 |
| 2002 | May 25 | Sep 30 | May 22 | Oct 13 |
| 2001 | Jun 14 | Sep 9 | Apr 17 | Sep 9 |
| 2000 | no data | Sep 24 | no data | Sep 25 |
"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.