Frost history / Mullan, ID
Mullan, ID: frost dates by year
Last spring and first fall frost at NOAA station USC00106230, 1976 to 2025, measured from daily minimum temperatures.
Elevation 3,201 ft, 47.466, -115.811. Download the data (JSON), NOAA daily records
Summary at 32°F
| Last spring frost | First fall frost | |
|---|---|---|
| Median | May 30 | Sep 15 |
| Earliest | Apr 28 (2023) | Aug 24 (1992) |
| Latest | Jul 3 (2018) | Oct 18 (2022) |
| Trend | 2.6 days earlier per decade | 1.0 days later per decade |
| Years with data | 30 | 30 |
At 28°F (hard freeze) the median last spring date is May 5 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 | Jun 28 | Sep 16 | Apr 24 | Oct 31 |
| 2024 | May 18 | Aug 25 | May 3 | Sep 29 |
| 2023 | Apr 28 | Sep 12 | Apr 22 | Oct 26 |
| 2022 | May 21 | Oct 18 | May 10 | Nov 5 |
| 2021 | May 28 | Oct 6 | Apr 21 | Oct 6 |
| 2020 | no data | Sep 7 | no data | Oct 21 |
| 2019 | May 3 | no data | May 1 | no data |
| 2018 | Jul 3 | Sep 18 | Jul 3 | Oct 9 |
| 2017 | May 14 | Oct 2 | Apr 15 | Oct 8 |
| 2016 | Jun 14 | Sep 12 | Mar 29 | Oct 11 |
| 2014 | May 12 | Sep 11 | May 11 | Oct 27 |
| 2013 | Apr 30 | Oct 3 | Apr 30 | Oct 3 |
| 1994 | May 2 | Oct 6 | Apr 29 | Oct 19 |
| 1993 | May 9 | Aug 25 | May 3 | Sep 22 |
| 1992 | May 22 | Aug 24 | May 12 | Sep 14 |
| 1991 | Jun 15 | Sep 22 | May 4 | Oct 4 |
| 1990 | Jun 5 | Oct 6 | May 9 | Oct 6 |
| 1989 | May 24 | Sep 11 | May 20 | Oct 3 |
| 1988 | Jun 2 | Sep 12 | Apr 27 | Oct 18 |
| 1987 | Jun 3 | Sep 17 | May 19 | Oct 10 |
| 1986 | May 23 | Sep 12 | May 23 | Oct 11 |
| 1985 | Jun 25 | Sep 20 | May 13 | Sep 22 |
| 1984 | Jun 2 | Sep 13 | May 22 | Sep 24 |
| 1983 | Jun 21 | Sep 10 | May 13 | Sep 20 |
| 1982 | Jun 8 | Sep 15 | May 11 | Sep 30 |
| 1981 | May 13 | Sep 23 | May 5 | Sep 24 |
| 1980 | Jun 4 | Aug 29 | Apr 12 | Oct 16 |
| 1979 | May 30 | Oct 3 | Apr 21 | Oct 3 |
| 1978 | May 30 | Sep 16 | May 5 | Oct 12 |
| 1977 | May 30 | Sep 25 | May 6 | Oct 3 |
| 1976 | Jun 26 | Sep 8 | May 18 | Oct 16 |
"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.