Hamilton, Montana Weather
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Climate of Hamilton: monthly averages
Based on 25 years of satellite and reanalysis data (2001-2025), August is usually the hottest month in Hamilton, with average daytime highs around 24°C. January is the coolest, when nights typically fall to about -13°C and frost is possible on the coldest nights. That is a wide yearly range of roughly 37°C, so the seasons feel very different from each other.
The area receives about 790 mm of rain in a typical year. Rainfall is modest in every month; December is the wettest at about 85 mm.
For outdoor plans and travel, July to August usually offer the most comfortable weather in Hamilton, with mild days and relatively little rain.
| Month | Avg high | Avg low | Rainfall | Humidity |
|---|---|---|---|---|
| Jan | -3° | -13° | 79 mm | 99% |
| Feb | -3° | -13° | 73 mm | 98% |
| Mar | 1° | -8° | 82 mm | 94% |
| Apr | 6° | -5° | 71 mm | 82% |
| May | 13° | 0° | 80 mm | 74% |
| Jun | 17° | 4° | 77 mm | 73% |
| Jul | 23° | 9° | 27 mm | 63% |
| Aug | 24° | 8° | 34 mm | 57% |
| Sep | 18° | 3° | 41 mm | 59% |
| Oct | 9° | -3° | 60 mm | 72% |
| Nov | 1° | -8° | 77 mm | 87% |
| Dec | -4° | -13° | 85 mm | 97% |
Source: NASA POWER (MERRA-2 reanalysis), averaged over the roughly 50 km grid area around Hamilton. Values describe typical conditions, not a forecast.
About Hamilton weather
Hamilton sits within Montana's continental climate, ranging from northern plains to Rocky Mountain terrain, about 71 km south of Missoula. Conditions turn hot with warm days and cool nights (June–August). By December, expect long, cold winters with heavy mountain snowfall. This page shows live, auto-refreshing weather for Hamilton: current conditions, an hourly breakdown, a 16-day outlook, a date-lookup tool for any past or future date, and real-time air quality, sourced from Open-Meteo. Local timezone: America/Denver.
Frequently asked questions
Hamilton is about 71 km south of Missoula, in Montana.
Hamilton sees long, cold winters with heavy mountain snowfall.
The live current conditions, hourly forecast and 16-day outlook above are pulled in real time for Hamilton's exact coordinates. No fixed schedule, the page updates whenever you load it.
August is usually the hottest month in Hamilton, with average daytime highs of about 24°C and nights around 8°C.
The coldest nights come in January, when the average low is about -13°C and daytime highs reach around -3°C. Frost is possible on clear, calm nights.
Hamilton receives about 790 mm of rain in a typical year. December is the wettest month at roughly 85 mm; no month averages more than 100 mm.
July to August usually offer the most comfortable weather in Hamilton, with mild daytime temperatures and little rain.
In November Hamilton typically sees daytime highs near 1°C and lows near -8°C, with about 77 mm of rain over the month and average humidity around 87%. Check the live forecast above for this week's actual conditions.
Up to 16 days ahead using the extended forecast and date picker above; further-out or historical dates use the same date lookup tool.
Live temperature for Hamilton is shown at the top of this page and refreshes automatically — see the hourly breakdown below for how it changes through the day.
Hamilton's day-to-day weather follows the broader pattern of Montana described above. See the hourly weather forecast or the air quality index for more detail.