Frost history / Rock Springs Fire Dept, WY
Rock Springs Fire Dept, WY: frost dates by year
Last spring and first fall frost at NOAA station USC00487847, 2003 to 2025, measured from daily minimum temperatures.
Elevation 6,270 ft, 41.578, -109.239. Download the data (JSON), NOAA daily records
Summary at 32°F
| Last spring frost | First fall frost | |
|---|---|---|
| Median | May 21 | Sep 21 |
| Earliest | May 1 (2018) | Sep 7 (2010) |
| Latest | Jun 10 (2019) | Oct 17 (2015) |
| Trend | 4.3 days earlier per decade | 5.2 days later per decade |
| Years with data | 21 | 20 |
At 28°F (hard freeze) the median last spring date is May 7 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 21 | Oct 8 | Apr 29 | Oct 13 |
| 2024 | May 24 | Oct 1 | May 11 | Oct 19 |
| 2023 | May 8 | Sep 24 | Apr 28 | Oct 14 |
| 2022 | Jun 1 | Oct 9 | May 21 | Oct 17 |
| 2021 | May 12 | Sep 21 | May 9 | Sep 21 |
| 2020 | May 25 | Sep 8 | Apr 21 | Sep 8 |
| 2019 | Jun 10 | Sep 18 | May 10 | Oct 3 |
| 2018 | May 1 | Sep 25 | Apr 25 | Sep 25 |
| 2017 | May 20 | Sep 17 | May 20 | Sep 26 |
| 2016 | May 12 | Sep 10 | May 3 | Oct 7 |
| 2015 | May 11 | Oct 17 | Apr 16 | Oct 28 |
| 2014 | May 14 | Sep 12 | May 13 | Sep 12 |
| 2013 | May 3 | Sep 20 | May 3 | Oct 4 |
| 2012 | May 30 | Oct 4 | May 8 | Oct 4 |
| 2011 | May 31 | no data | May 4 | no data |
| 2010 | May 27 | Sep 7 | May 8 | Oct 14 |
| 2008 | no data | Sep 24 | no data | Oct 11 |
| 2007 | Jun 8 | Sep 30 | May 7 | Oct 22 |
| 2006 | May 29 | Sep 22 | May 10 | Oct 10 |
| 2005 | Jun 10 | Sep 13 | May 1 | Oct 6 |
| 2004 | May 15 | no data | Apr 29 | no data |
| 2003 | May 20 | Sep 13 | May 19 | Sep 18 |
"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.