| Month | Temp. (min) | Temp. (max) | Temp. (avg) | Precipitation |
| January | 17°F | 37°F | 27°F | 0.8" |
| February | 17°F | 40°F | 28°F | 0.7" |
| March | 25°F | 50°F | 36°F | 0.8" |
| April | 31°F | 58°F | 43°F | 2.5" |
| May | 38°F | 66°F | 52°F | 2.5" |
| June | 46°F | 76°F | 61°F | 2.6" |
| July | 53°F | 89°F | 71°F | 1.1" |
| August | 51°F | 86°F | 68°F | 1.2" |
| September | 44°F | 75°F | 58°F | 1.6" |
| October | 35°F | 60°F | 46°F | 1.2" |
| November | 25°F | 47°F | 35°F | 0.9" |
| December | 15°F | 34°F | 24°F | 1.2" |
| Index | Vaughn | Montana | National |
| Air quality index | 21 | 34 | 42 |
| Pollution index | 260,100 | 834,473 | 2,726,193 |
| Measurement | Total |
| Days measured | 363 |
| Days with good air quality | 350 |
| Days with moderate air quality | 12 |
| Days w/ poor A.Q. for sensitive groups | 1 |
| Days with unhealthy air quality | 0 |
| Pollutant | Total |
| Arsenic | 0.000% |
| Benzene | 0.004% |
| Carbon Tetrachloride | 0.000% |
| Lead | 0.002% |
| Mercury | 0.000% |
| City | Population | Air Quality Index | National Avg. |
| Great Falls, MT | 60,209 | 21 | 58.0% |
| Power, MT | 158 | 21 | 58.0% |
| Black Eagle, MT | 868 | 21 | 58.0% |
| Sun Prairie, MT | 1,649 | 21 | 58.0% |
| Fort Shaw, MT | 144 | 21 | 58.0% |
| Vaughn, MT | 906 | 21 | 58.0% |
| City | Population | Air Quality Index | National Avg. |
| Hooper Bay, AK | 906 | 31 | 38.0% |
| La Jara, CO | 906 | 15 | 70.0% |
| Lyons, IN | 906 | 1 | 98.0% |
| Parks, LA | 906 | 41 | 18.0% |
| Barnes Lake-Millers Lake, MI | 906 | 38 | 24.0% |
| Vaughn, MT | 906 | 21 | 58.0% |