Frost history / Rio Grande Rsvr, CO
Rio Grande Rsvr, CO: frost dates by year
Last spring and first fall frost at NOAA station USC00057050, 1978 to 2025, measured from daily minimum temperatures.
Elevation 9,492 ft, 37.722, -107.267. Download the data (JSON), NOAA daily records
Summary at 32°F
| Last spring frost | First fall frost | |
|---|---|---|
| Median | Jun 25 | Sep 6 |
| Earliest | May 27 (2025) | Aug 1 (1978) |
| Latest | Jul 31 (1990) | Sep 20 (2009) |
| Trend | 8.4 days earlier per decade | 6.1 days later per decade |
| Years with data | 31 | 30 |
At 28°F (hard freeze) the median last spring date is Jun 9 and the median first fall date is Sep 15.
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 | Aug 3 | May 21 | Oct 5 |
| 2024 | May 31 | Sep 6 | May 22 | Oct 21 |
| 2023 | Jun 25 | Sep 19 | Jun 2 | Oct 5 |
| 2022 | Jun 21 | Sep 16 | Jun 1 | Oct 9 |
| 2018 | Jun 4 | Sep 13 | May 22 | Sep 20 |
| 2017 | Jun 14 | Sep 16 | May 29 | Sep 24 |
| 2016 | Jun 15 | Sep 14 | May 28 | Sep 15 |
| 2015 | May 31 | no data | May 24 | no data |
| 2014 | Jun 20 | Sep 13 | Jun 15 | Oct 2 |
| 2013 | Jun 5 | Sep 11 | Jun 1 | Sep 11 |
| 2011 | Jun 23 | Sep 18 | Jun 1 | Sep 22 |
| 2010 | Jul 5 | Sep 6 | May 30 | Sep 11 |
| 2009 | no data | Sep 20 | no data | Sep 22 |
| 2005 | Jun 14 | Sep 13 | Jun 11 | Sep 15 |
| 2004 | Jul 5 | no data | May 31 | no data |
| 2001 | Jun 16 | Aug 23 | Jun 15 | Sep 9 |
| 2000 | no data | Sep 10 | no data | Sep 24 |
| 1999 | no data | Sep 4 | no data | Sep 21 |
| 1996 | Jun 3 | no data | May 29 | no data |
| 1994 | no data | Sep 15 | no data | Sep 15 |
| 1993 | Jun 25 | no data | Jun 9 | no data |
| 1992 | Jul 13 | Aug 25 | Jun 3 | Aug 25 |
| 1990 | Jul 31 | Aug 1 | Jun 17 | Sep 21 |
| 1989 | Jul 2 | Aug 22 | Jun 22 | Aug 28 |
| 1988 | Jun 16 | Sep 14 | Jun 10 | Sep 14 |
| 1987 | Jul 20 | Aug 17 | Jun 14 | Aug 28 |
| 1986 | Jul 17 | Sep 2 | May 31 | Sep 11 |
| 1985 | Jul 3 | Aug 11 | Jul 2 | Sep 6 |
| 1984 | Jul 31 | Aug 8 | Jun 23 | Sep 2 |
| 1983 | Jul 12 | Sep 15 | Jun 21 | Sep 20 |
| 1982 | Jul 10 | no data | Jun 20 | no data |
| 1981 | Jun 19 | Aug 17 | Jun 16 | Sep 19 |
| 1980 | Jul 30 | Aug 2 | Jul 23 | Aug 11 |
| 1979 | Jun 26 | Aug 19 | Jun 26 | Sep 13 |
| 1978 | Jul 29 | Aug 1 | Jul 22 | Aug 8 |
"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.