Frost history / Anaconda, MT
Anaconda, MT: frost dates by year
Last spring and first fall frost at NOAA station USC00240199, 1982 to 2025, measured from daily minimum temperatures.
Elevation 5,230 ft, 46.131, -112.933. Download the data (JSON), NOAA daily records
Summary at 32°F
| Last spring frost | First fall frost | |
|---|---|---|
| Median | Jun 14 | Sep 11 |
| Earliest | May 13 (2000) | Aug 12 (1993) |
| Latest | Jul 30 (1995) | Oct 12 (2010) |
| Trend | 3.6 days later per decade | 1.8 days later per decade |
| Years with data | 34 | 37 |
At 28°F (hard freeze) the median last spring date is May 18 and the median first fall date is Sep 22.
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 | Jun 24 | Sep 23 | May 21 | Oct 6 |
| 2024 | Jun 19 | Sep 21 | May 31 | Sep 30 |
| 2023 | Jun 22 | Sep 20 | Jun 20 | Sep 28 |
| 2022 | Jun 26 | Sep 8 | May 21 | Oct 14 |
| 2021 | no data | Aug 24 | no data | Sep 17 |
| 2018 | Jun 12 | no data | Apr 25 | no data |
| 2017 | Jun 11 | Sep 14 | May 17 | Sep 23 |
| 2016 | no data | Oct 6 | no data | Oct 7 |
| 2011 | Jun 16 | Sep 3 | May 5 | Oct 9 |
| 2010 | Jun 1 | Oct 12 | May 21 | Oct 12 |
| 2009 | Jun 23 | Sep 21 | May 21 | Oct 3 |
| 2008 | Jun 11 | Sep 1 | May 13 | Oct 9 |
| 2007 | Jun 26 | Sep 9 | May 5 | Sep 25 |
| 2006 | May 30 | Sep 1 | May 10 | Sep 18 |
| 2005 | Jun 7 | Sep 11 | May 2 | Sep 11 |
| 2004 | Jun 16 | Sep 3 | May 25 | Sep 21 |
| 2003 | Jun 23 | Sep 14 | May 20 | Sep 18 |
| 2002 | Jun 11 | Sep 21 | May 23 | Sep 21 |
| 2001 | Jun 16 | Oct 5 | May 17 | Oct 5 |
| 2000 | May 13 | Sep 3 | May 9 | Sep 21 |
| 1999 | no data | Sep 26 | no data | Sep 27 |
| 1998 | Jun 5 | Sep 30 | Apr 26 | Oct 3 |
| 1997 | Jul 11 | Sep 5 | May 20 | Sep 19 |
| 1996 | Jun 20 | Aug 19 | May 10 | Sep 23 |
| 1995 | Jul 30 | Aug 14 | Jun 20 | Sep 21 |
| 1994 | Jul 3 | Sep 5 | Apr 29 | Oct 3 |
| 1993 | Jun 23 | Aug 12 | Apr 27 | Sep 21 |
| 1992 | May 16 | Aug 23 | May 12 | Aug 23 |
| 1991 | Jun 18 | Sep 18 | May 5 | Sep 22 |
| 1990 | Jun 4 | Oct 2 | May 20 | Oct 6 |
| 1989 | May 31 | Sep 6 | May 26 | Sep 11 |
| 1988 | Jun 30 | Sep 11 | May 18 | Oct 18 |
| 1987 | Jun 3 | Sep 17 | Jun 2 | Sep 17 |
| 1986 | May 23 | Sep 12 | May 23 | Sep 22 |
| 1985 | May 31 | Sep 19 | May 13 | Sep 20 |
| 1984 | Jun 2 | Sep 13 | May 25 | Sep 14 |
| 1983 | May 16 | Sep 10 | May 14 | Sep 19 |
| 1982 | no data | Sep 11 | no data | Sep 14 |
"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.