Montana has warm, dry summers and cold, snowy winters: NOAA's 1991–2020 normals for Missoula International Airport give highs of 84.3–85.4°F in July and August and 30.9°F in December, with 11.6 inches of snow in December and June the wettest month at 2.14 inches. Helena and Bozeman are similar. Choose by activity; we have no verified dataset for road closures, wildfire smoke, crowds or prices.
Month-by-month climate table
| Month | Normal high | Normal low | Normal precipitation | Normal snowfall | Verified notes |
|---|---|---|---|---|---|
| January | 31.6°F | 18.0°F | 0.96 in | 9.9 in | — |
| February | 37.0°F | 20.9°F | 0.88 in | 8.5 in | — |
| March | 47.9°F | 26.8°F | 0.92 in | 5.0 in | — |
| April | 56.1°F | 32.3°F | 1.36 in | 1.3 in | Glacier winter pass rate ends Apr 30 |
| May | 66.2°F | 39.8°F | 1.77 in | 0.3 in | — |
| June | 73.2°F | 46.3°F | 2.14 in | 0.0 in | — |
| July | 85.4°F | 51.5°F | 0.85 in | 0.0 in | — |
| August | 84.3°F | 50.1°F | 0.83 in | 0.0 in | — |
| September | 72.6°F | 42.4°F | 0.96 in | 0.1 in | — |
| October | 55.7°F | 32.4°F | 1.18 in | 0.9 in | — |
| November | 39.9°F | 24.6°F | 1.18 in | 5.4 in | Glacier winter pass rate starts Nov 1 |
| December | 30.9°F | 17.8°F | 1.08 in | 11.6 in | — |
Source: NOAA NCEI U.S. Climate Normals 1991–2020, Missoula International Airport (USW00024153), retrieved October 20, 2026. Normals are 30-year averages; actual weather varies. Notes are from the National Park Service (via a search summary).
Missoula vs Helena vs Bozeman
| Station | January high / low | July high / low | Wettest month | Peak snowfall |
|---|---|---|---|---|
| Missoula | 31.6°F / 18.0°F | 85.4°F / 51.5°F | June (2.14 in) | 11.6 in (December) |
| Helena | 32.4°F / 13.5°F | 86.1°F / 55.1°F | June (2.21 in) | 7.7 in (December) |
| Bozeman | 32.2°F / 10.2°F | 85.4°F / 49.4°F | June (2.54 in) | not reported |
How to choose your month
- Warmest: July and August (highs 84–86°F).
- Coldest: December–February (Missoula highs 30.9–37.0°F).
- Snowiest: December and January at Missoula.
Limits of this guide
Normals describe typical conditions, not forecasts, and we have no verified dataset for mountain road conditions, wildfire smoke, event dates, crowds or prices by month, so this page makes no such claims. Use the National Weather Service for forecasts.