| Month | Temp. (min) | Temp. (max) | Temp. (avg) | Precipitation |
| January | 10°F | 29°F | 19°F | 0.5" |
| February | 11°F | 32°F | 20°F | 0.4" |
| March | 23°F | 48°F | 33°F | 1.5" |
| April | 32°F | 58°F | 44°F | 2.8" |
| May | 42°F | 68°F | 54°F | 7.0" |
| June | 52°F | 79°F | 65°F | 3.1" |
| July | 59°F | 89°F | 73°F | 4.0" |
| August | 56°F | 86°F | 70°F | 3.9" |
| September | 46°F | 76°F | 60°F | 3.8" |
| October | 34°F | 59°F | 45°F | 2.8" |
| November | 21°F | 44°F | 31°F | 0.6" |
| December | 9°F | 29°F | 18°F | 0.6" |
| Index | West Glendive | Montana | National |
| Air quality index | 34 | 34 | 42 |
| Pollution index | 155,479 | 834,473 | 2,726,193 |
| Measurement | Total |
| Days measured | 365 |
| Days with good air quality | 309 |
| Days with moderate air quality | 53 |
| Days w/ poor A.Q. for sensitive groups | 3 |
| Days with unhealthy air quality | 0 |
| 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. |
| Glendive, MT | 5,228 | 34 | 32.0% |
| West Glendive, MT | 1,694 | 34 | 32.0% |
| City | Population | Air Quality Index | National Avg. |
| Pittsford, NY | 1,694 | 37 | 26.0% |
| Shepherdstown, WV | 1,694 | 40 | 20.0% |
| Lazy Mountain, AK | 1,693 | 31 | 38.0% |
| Searles Valley, CA | 1,693 | 15 | 70.0% |
| New Plymouth, ID | 1,693 | 36 | 28.0% |
| West Glendive, MT | 1,694 | 34 | 32.0% |