| Month | High | Low | Rain | Wet days | Score |
|---|---|---|---|---|---|
| January | 1.1° | -6.7° | — | — | 26 |
| February | 3.6° | -6.2° | — | — | 29 |
| March | 9.2° | -3° | — | — | 52 |
| April | 13.8° | -0.2° | — | — | 71 |
| May | 19.2° | 4.2° | — | — | 91 |
| June | 23.8° | 8° | — | — | 94 |
| July | 31.5° | 11.4° | — | — | 76 |
| August | 29.8° | 10.5° | — | — | 83 |
| September | 23.3° | 6.3° | — | — | 94 |
| October | 13.8° | 0.8° | — | — | 72 |
| November | 5° | -4° | — | — | 37 |
| December | 0.2° | -7° | — | — | 26 |
January in Missoula averages a daily high of 1.1°C with nights around -6.7°C. A hard month to visit for comfort alone.
February in Missoula averages a daily high of 3.6°C with nights around -6.2°C. A hard month to visit for comfort alone.
March in Missoula averages a daily high of 9.2°C with nights around -3°C. Demanding conditions — pack for it and plan indoor options.
April in Missoula averages a daily high of 13.8°C with nights around -0.2°C. Generally workable, with some weather to plan around.
May in Missoula averages a daily high of 19.2°C with nights around 4.2°C. Comfortable conditions for being outdoors all day.
June in Missoula averages a daily high of 23.8°C with nights around 8°C. Comfortable conditions for being outdoors all day.
July in Missoula averages a daily high of 31.5°C with nights around 11.4°C. Comfortable conditions for being outdoors all day.
August in Missoula averages a daily high of 29.8°C with nights around 10.5°C. Comfortable conditions for being outdoors all day.
September in Missoula averages a daily high of 23.3°C with nights around 6.3°C. Comfortable conditions for being outdoors all day.
October in Missoula averages a daily high of 13.8°C with nights around 0.8°C. Generally workable, with some weather to plan around.
November in Missoula averages a daily high of 5°C with nights around -4°C. Demanding conditions — pack for it and plan indoor options.
December in Missoula averages a daily high of 0.2°C with nights around -7°C. A hard month to visit for comfort alone.
Each month scores out of 100. It starts at 100 and loses points for daytime highs outside a 20–27°C band, for wet days, and for nights below 2°C. Nothing else is weighted in — no crowd data, no prices, no opinion. Missoula peaks at 94.
Based on 30 years of records, May–June scores highest for comfort in Missoula, balancing daytime temperature against rainfall.
July is the warmest, averaging a daily high of 31.5°C.
January is the wettest, averaging —mm of rain across roughly — wet days.
December is the coolest month, with average daily highs around 0.2°C.