Frost history / Big Horn, WY
Big Horn, WY: frost dates by year
Last spring and first fall frost at NOAA station USC00480680, 2006 to 2025, measured from daily minimum temperatures.
Elevation 4,208 ft, 44.683, -107.009. Download the data (JSON), NOAA daily records
Summary at 32°F
| Last spring frost | First fall frost | |
|---|---|---|
| Median | May 20 | Sep 28 |
| Earliest | Apr 24 (2023) | Sep 4 (2021) |
| Latest | Jun 19 (2024) | Oct 17 (2022) |
| Trend | 5.9 days earlier per decade | 2.6 days later per decade |
| Years with data | 19 | 20 |
At 28°F (hard freeze) the median last spring date is May 2 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 |
|---|---|---|---|---|
| 2025 | May 7 | Oct 14 | Apr 23 | Oct 21 |
| 2024 | Jun 19 | Sep 22 | May 4 | Oct 25 |
| 2023 | Apr 24 | Oct 6 | Apr 24 | Oct 14 |
| 2022 | May 24 | Oct 17 | May 22 | Oct 26 |
| 2021 | May 23 | Sep 4 | May 11 | Sep 17 |
| 2020 | May 10 | Sep 8 | May 8 | Sep 9 |
| 2019 | May 23 | Oct 1 | May 2 | Oct 3 |
| 2018 | Apr 25 | Sep 28 | Apr 25 | Oct 11 |
| 2017 | May 20 | Sep 17 | Apr 30 | Oct 3 |
| 2016 | May 14 | Oct 5 | Apr 15 | Oct 6 |
| 2015 | May 21 | Oct 16 | Apr 20 | Oct 16 |
| 2014 | May 9 | Sep 11 | Apr 18 | Sep 12 |
| 2013 | May 5 | Sep 27 | May 2 | Oct 5 |
| 2012 | May 12 | Oct 5 | May 6 | Oct 6 |
| 2011 | May 13 | Sep 21 | May 2 | Oct 26 |
| 2010 | May 23 | Oct 16 | May 9 | Oct 28 |
| 2009 | Jun 8 | Sep 28 | May 2 | Sep 28 |
| 2008 | Jun 12 | Sep 8 | May 3 | Oct 12 |
| 2007 | May 24 | Sep 10 | Apr 20 | Oct 16 |
| 2006 | no data | Oct 10 | no data | Oct 10 |
"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.