Frost history / Ryegate, MT
Ryegate, MT: frost dates by year
Last spring and first fall frost at NOAA station USC00247261, 2000 to 2025, measured from daily minimum temperatures.
Elevation 3,650 ft, 46.299, -109.256. Download the data (JSON) · NOAA daily records
Summary at 32°F
| Last spring frost | First fall frost | |
|---|---|---|
| Median | May 18 | Sep 23 |
| Earliest | Apr 26 (2018) | Aug 23 (2015) |
| Latest | May 30 (2021) | Oct 16 (2022) |
| Trend | 1.1 days later per decade | 5.0 days later per decade |
| Years with data | 15 | 20 |
At 28°F (hard freeze) the median last spring date is May 8 and the median first fall date is Oct 5.
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 | no data | Oct 5 | no data | Oct 7 |
| 2024 | May 24 | Sep 30 | May 5 | Oct 22 |
| 2023 | no data | Oct 6 | no data | Oct 24 |
| 2022 | no data | Oct 16 | no data | Oct 23 |
| 2021 | May 30 | Sep 17 | May 26 | Sep 17 |
| 2019 | May 18 | Sep 29 | May 3 | Sep 30 |
| 2018 | Apr 26 | Sep 26 | Apr 26 | Oct 1 |
| 2017 | May 19 | Sep 17 | Apr 19 | Oct 4 |
| 2016 | May 17 | Oct 11 | Apr 17 | Oct 11 |
| 2015 | May 21 | Aug 23 | May 11 | Oct 16 |
| 2014 | May 13 | Sep 12 | May 13 | Sep 12 |
| 2013 | May 11 | Sep 20 | May 2 | Oct 5 |
| 2012 | May 29 | Sep 12 | May 11 | Oct 6 |
| 2011 | no data | Sep 4 | no data | Sep 21 |
| 2010 | May 23 | Oct 13 | May 8 | Oct 13 |
| 2009 | no data | Sep 28 | no data | Sep 28 |
| 2007 | May 16 | no data | May 15 | no data |
| 2006 | May 14 | Oct 10 | May 5 | Oct 12 |
| 2004 | May 25 | Sep 21 | May 19 | Sep 21 |
| 2003 | no data | Sep 13 | no data | Sep 19 |
| 2002 | no data | Sep 21 | no data | Sep 21 |
| 2000 | May 13 | no data | May 8 | 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 1991–2020 frost probabilities.