| Month | Temp. (min) | Temp. (max) | Temp. (avg) | Precipitation |
| January | 15°F | 35°F | 25°F | 1.2" |
| February | 23°F | 44°F | 32°F | 0.6" |
| March | 25°F | 51°F | 37°F | 1.2" |
| April | 31°F | 57°F | 43°F | 2.1" |
| May | 38°F | 66°F | 51°F | 4.2" |
| June | 49°F | 77°F | 63°F | 3.5" |
| July | 54°F | 87°F | 71°F | 3.1" |
| August | 52°F | 85°F | 68°F | 3.7" |
| September | 46°F | 75°F | 59°F | 4.6" |
| October | 35°F | 60°F | 46°F | 4.2" |
| November | 24°F | 47°F | 35°F | 2.0" |
| December | 16°F | 37°F | 26°F | 1.8" |
| Index | Grass Range | Montana | National |
| Air quality index | 21 | 34 | 42 |
| Pollution index | 231,483 | 834,473 | 2,726,193 |
| Measurement | Total |
| Days measured | 362 |
| Days with good air quality | 357 |
| Days with moderate air quality | 4 |
| Days w/ poor A.Q. for sensitive groups | 0 |
| Days with unhealthy air quality | 1 |
| Pollutant | Total |
| Arsenic | 0.000% |
| Benzene | 0.001% |
| Carbon Tetrachloride | 0.000% |
| Lead | 0.000% |
| Mercury | 0.000% |
| City | Population | Air Quality Index | National Avg. |
| Grass Range, MT | 121 | 21 | 58.0% |
| City | Population | Air Quality Index | National Avg. |
| Alcan Border, AK | 121 | 38 | 24.0% |
| Tenakee Springs, AK | 121 | 20 | 60.0% |
| Providence, AL | 121 | 36 | 28.0% |
| Rondo, AR | 121 | 45 | 10.0% |
| Pine Level, FL | 121 | 41 | 18.0% |
| Grass Range, MT | 121 | 21 | 58.0% |
Here are the best places to live in Montana
These are the largest cities in Montana
Check out the 10 safest cities in Montana
See the best places to live in Grass Range