Frost history / Alberton, MT
Alberton, MT: frost dates by year
Last spring and first fall frost at NOAA station USC00240075, 1959 to 2025, measured from daily minimum temperatures.
Elevation 3,060 ft, 47.004, -114.478. Download the data (JSON), NOAA daily records
Summary at 32°F
| Last spring frost | First fall frost | |
|---|---|---|
| Median | May 23 | Sep 21 |
| Earliest | Apr 29 (2023) | Aug 22 (1966) |
| Latest | Jul 7 (1971) | Oct 18 (2023) |
| Trend | 2.0 days earlier per decade | 3.1 days later per decade |
| Years with data | 35 | 34 |
At 28°F (hard freeze) the median last spring date is May 6 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 19 | Oct 6 | May 6 | Oct 22 |
| 2024 | May 31 | Sep 30 | May 4 | Oct 21 |
| 2023 | Apr 29 | Oct 18 | Apr 24 | Oct 25 |
| 2022 | May 12 | Oct 16 | May 11 | Oct 17 |
| 2021 | May 29 | Sep 17 | Apr 27 | Oct 8 |
| 2020 | Jun 15 | Sep 8 | May 5 | Oct 22 |
| 2019 | May 4 | Sep 29 | May 3 | Oct 1 |
| 2018 | May 23 | Sep 19 | Apr 24 | Oct 11 |
| 2017 | May 9 | Sep 24 | Apr 17 | Oct 4 |
| 2016 | Jun 15 | Sep 13 | Apr 2 | Sep 13 |
| 2015 | May 11 | Sep 28 | Apr 30 | Sep 29 |
| 2014 | May 30 | Sep 11 | May 13 | Sep 12 |
| 2013 | May 25 | Sep 27 | May 3 | Oct 4 |
| 2012 | Jun 7 | Sep 12 | May 12 | Oct 4 |
| 2011 | May 17 | Sep 29 | May 2 | Oct 19 |
| 2010 | May 22 | Oct 12 | May 10 | Oct 12 |
| 2009 | May 22 | Sep 21 | May 21 | Oct 5 |
| 2008 | May 14 | Oct 9 | May 13 | Oct 9 |
| 2007 | May 6 | Sep 10 | May 6 | Sep 30 |
| 2006 | May 13 | Sep 1 | May 10 | Oct 10 |
| 2005 | May 24 | Sep 22 | Apr 30 | Oct 10 |
| 2004 | May 26 | Oct 5 | May 13 | Oct 11 |
| 2003 | May 20 | Oct 4 | May 17 | Oct 11 |
| 2002 | May 15 | Sep 21 | May 11 | Oct 1 |
| 1999 | no data | Sep 28 | no data | Sep 28 |
| 1971 | Jul 7 | no data | May 21 | no data |
| 1970 | May 14 | Sep 10 | Apr 27 | Sep 12 |
| 1969 | Jun 14 | Sep 4 | May 3 | Sep 15 |
| 1968 | May 25 | Oct 2 | May 11 | Oct 2 |
| 1967 | May 26 | Oct 4 | May 26 | Oct 20 |
| 1966 | May 23 | Aug 22 | May 23 | Oct 9 |
| 1965 | Jun 28 | Sep 2 | May 18 | Sep 16 |
| 1962 | Jun 6 | Sep 4 | Apr 30 | Oct 17 |
| 1961 | May 11 | no data | Apr 22 | no data |
| 1960 | May 23 | Sep 8 | May 22 | Sep 22 |
| 1959 | May 27 | Sep 9 | May 12 | Oct 1 |
"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.