Weather history and climate summary information is available for the following locations:
- Billings
- Glasgow
- Great Falls
- Helena
- Lewistown
- Miles City
- Missoula
Warmest January Days
The warmest January days in Montana are:
| Lewistown, Montana | 1981 | 73°F |
| Miles City, Montana | 1992 | 72°F |
| Lewistown, Montana | 2003 | 68°F |
| Great Falls, Montana | 1992 | 66.9°F |
| Great Falls, Montana | 1981 | 66.9°F |
Coldest January Days
The coldest January days in Montana were:
| Glasgow, Montana | 1943 | -40.5°F |
| Glasgow, Montana | 1996 | -39.1°F |
| Glasgow, Montana | 1982 | -38.9°F |
| Helena, Montana | 1996 | -37.1°F |
| Glasgow, Montana | 1989 | -36.9°F |
Wettest January Days
The wettest single days in January occurred:
| Great Falls, Montana | 1973 | 3.9 inches |
| Missoula, Montana | 1973 | 2.6 inches |
| Helena, Montana | 1973 | 2.4 inches |
| Billings, Montana | 1973 | 2.2 inches |
| Glasgow, Montana | 1973 | 1.7 inches |