Frost history / Billings Wfo, MT
Billings Wfo, MT: frost dates by year
Last spring and first fall frost at NOAA station USC00240801, 1999 to 2025, measured from daily minimum temperatures.
Elevation 3,185 ft, 45.750, -108.570. Download the data (JSON), NOAA daily records
Summary at 32°F
| Last spring frost | First fall frost | |
|---|---|---|
| Median | May 9 | Oct 4 |
| Earliest | Apr 19 (2025) | Sep 9 (2020) |
| Latest | May 26 (2012) | Oct 24 (2023) |
| Trend | 6.7 days earlier per decade | 6.0 days later per decade |
| Years with data | 26 | 24 |
At 28°F (hard freeze) the median last spring date is Apr 22 and the median first fall date is Oct 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 | Apr 19 | Oct 21 | Apr 14 | Oct 28 |
| 2024 | May 4 | Oct 19 | May 4 | Oct 30 |
| 2023 | Apr 28 | Oct 24 | Apr 21 | Oct 25 |
| 2022 | May 10 | Oct 24 | Apr 25 | Oct 26 |
| 2021 | Apr 24 | Sep 17 | Apr 22 | Nov 1 |
| 2020 | May 8 | Sep 9 | Apr 16 | Oct 16 |
| 2019 | May 10 | Sep 30 | Apr 13 | Oct 9 |
| 2018 | Apr 25 | Sep 30 | Apr 14 | Oct 12 |
| 2017 | May 19 | Oct 4 | Mar 13 | Oct 4 |
| 2016 | Apr 28 | no data | Apr 17 | no data |
| 2015 | May 11 | Oct 16 | May 11 | Oct 29 |
| 2014 | May 7 | Sep 12 | Apr 14 | Sep 12 |
| 2013 | May 5 | Oct 4 | May 2 | Oct 5 |
| 2012 | May 26 | Oct 5 | Apr 10 | Oct 6 |
| 2011 | May 5 | Oct 9 | Apr 25 | Oct 26 |
| 2010 | May 23 | no data | May 8 | no data |
| 2009 | May 10 | no data | May 2 | no data |
| 2008 | May 3 | Oct 9 | Apr 27 | Oct 9 |
| 2007 | Apr 20 | Sep 30 | Apr 14 | Oct 27 |
| 2006 | May 11 | Oct 10 | May 5 | Oct 13 |
| 2005 | May 13 | Oct 4 | May 12 | Oct 5 |
| 2004 | May 25 | Sep 22 | May 13 | Oct 25 |
| 2003 | May 20 | Sep 18 | Apr 7 | Oct 29 |
| 2002 | May 23 | Sep 22 | May 9 | Oct 19 |
| 2001 | May 7 | Oct 5 | Apr 17 | Oct 5 |
| 2000 | May 13 | Sep 21 | Apr 16 | Sep 22 |
| 1999 | no data | Sep 27 | no data | Oct 3 |
"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.