Frost history / Black Forest 6WNW, CO
Black Forest 6WNW, CO: frost dates by year
Last spring and first fall frost at NOAA station USC00050756, 2010 to 2022, measured from daily minimum temperatures.
Elevation 6,957 ft, 39.029, -104.802. Download the data (JSON), NOAA daily records
Summary at 32°F
| Last spring frost | First fall frost | |
|---|---|---|
| Median | May 12 | Oct 8 |
| Earliest | May 4 (2018) | Sep 9 (2020) |
| Latest | May 24 (2022) | Oct 28 (2015) |
| Trend | 2.3 days later per decade | 8.7 days earlier per decade |
| Years with data | 12 | 12 |
At 28°F (hard freeze) the median last spring date is May 4 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 |
|---|---|---|---|---|
| 2022 | May 24 | no data | May 22 | no data |
| 2021 | May 12 | Oct 14 | Apr 23 | Oct 16 |
| 2020 | May 12 | Sep 9 | Apr 18 | Sep 9 |
| 2019 | May 23 | Oct 8 | May 22 | Oct 10 |
| 2018 | May 4 | Oct 10 | Apr 26 | Oct 11 |
| 2017 | May 21 | Oct 9 | May 21 | Oct 10 |
| 2016 | May 12 | Oct 7 | May 3 | Oct 20 |
| 2015 | May 12 | Oct 28 | May 12 | Oct 28 |
| 2014 | May 16 | Sep 12 | May 14 | Oct 3 |
| 2013 | May 10 | Sep 29 | May 4 | Oct 5 |
| 2012 | May 12 | Oct 4 | Apr 16 | Oct 4 |
| 2011 | May 21 | Oct 8 | May 5 | Oct 19 |
| 2010 | no data | Oct 26 | no data | Oct 27 |
"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.