Frost history / Divide 4NW, CO
Divide 4NW, CO: frost dates by year
Last spring and first fall frost at NOAA station USC00052294, 2011 to 2025, measured from daily minimum temperatures.
Elevation 9,134 ft, 38.961, -105.216. Download the data (JSON), NOAA daily records
Summary at 32°F
| Last spring frost | First fall frost | |
|---|---|---|
| Median | Jun 1 | Sep 22 |
| Earliest | May 21 (2018) | Sep 8 (2020) |
| Latest | Jun 24 (2019) | Oct 19 (2024) |
| Trend | 0.7 days earlier per decade | 8.8 days later per decade |
| Years with data | 14 | 15 |
At 28°F (hard freeze) the median last spring date is May 22 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)
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 |
|---|---|---|---|---|
| 2025 | May 28 | Oct 8 | May 21 | Oct 14 |
| 2024 | May 26 | Oct 19 | May 23 | Oct 25 |
| 2023 | Jun 2 | Sep 16 | Apr 30 | Oct 7 |
| 2022 | Jun 2 | Oct 8 | May 26 | Oct 17 |
| 2021 | Jun 2 | Sep 21 | May 13 | Oct 10 |
| 2020 | Jun 10 | Sep 8 | Jun 10 | Sep 8 |
| 2019 | Jun 24 | Sep 22 | May 31 | Oct 8 |
| 2018 | May 21 | Sep 26 | May 5 | Oct 6 |
| 2017 | May 30 | Sep 25 | May 29 | Oct 7 |
| 2016 | May 29 | Sep 10 | May 28 | Sep 24 |
| 2015 | May 29 | Sep 19 | May 24 | Oct 24 |
| 2014 | Jun 10 | Sep 12 | May 15 | Sep 12 |
| 2013 | Jun 2 | Sep 28 | May 22 | Sep 28 |
| 2012 | May 28 | Oct 4 | May 15 | Oct 4 |
| 2011 | no data | Sep 22 | no data | Oct 7 |
"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.