Frost history / Alamosa 1E, CO
Alamosa 1E, CO: frost dates by year
Last spring and first fall frost at NOAA station USC00050128, 2006 to 2025, measured from daily minimum temperatures.
Elevation 7,540 ft, 37.470, -105.857. Download the data (JSON), NOAA daily records
Summary at 32°F
| Last spring frost | First fall frost | |
|---|---|---|
| Median | Jun 1 | Sep 20 |
| Earliest | May 6 (2009) | Aug 9 (2009) |
| Latest | Jun 17 (2006) | Oct 13 (2015) |
| Trend | 5.4 days earlier per decade | 12.5 days later per decade |
| Years with data | 20 | 19 |
At 28°F (hard freeze) the median last spring date is May 22 and the median first fall date is Sep 28.
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 27 | Sep 24 | May 20 | Oct 5 |
| 2024 | May 30 | Sep 23 | May 22 | Oct 16 |
| 2023 | Jun 2 | Sep 20 | May 9 | Oct 5 |
| 2022 | May 31 | Oct 6 | May 25 | Oct 10 |
| 2021 | May 28 | Sep 21 | May 25 | Oct 11 |
| 2020 | Jun 10 | Sep 9 | May 21 | Sep 9 |
| 2019 | May 31 | Sep 22 | May 29 | Sep 22 |
| 2018 | Jun 3 | Sep 26 | May 5 | Oct 6 |
| 2017 | May 21 | Sep 18 | May 20 | Sep 25 |
| 2016 | May 28 | Sep 16 | May 12 | Sep 24 |
| 2015 | May 25 | Oct 13 | May 17 | Oct 15 |
| 2014 | May 16 | Sep 30 | May 14 | Oct 3 |
| 2013 | Jun 4 | Sep 24 | May 27 | Sep 28 |
| 2012 | Jun 11 | Sep 14 | May 30 | Sep 18 |
| 2011 | Jun 15 | Sep 18 | May 31 | Sep 23 |
| 2010 | Jun 15 | Sep 1 | May 26 | Oct 9 |
| 2009 | May 6 | Aug 9 | Apr 30 | Sep 22 |
| 2008 | Jun 13 | Sep 4 | Jun 13 | Sep 13 |
| 2007 | Jun 9 | Sep 13 | Jun 8 | Sep 25 |
| 2006 | Jun 17 | no data | May 13 | no 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.