| Month | Temp. (min) | Temp. (max) | Temp. (avg) | Precipitation |
| January | n/a°F | n/a°F | n/a°F | n/a |
| February | n/a°F | n/a°F | n/a°F | n/a |
| March | n/a°F | n/a°F | n/a°F | n/a |
| April | n/a°F | n/a°F | n/a°F | n/a |
| May | n/a°F | n/a°F | n/a°F | n/a |
| June | n/a°F | n/a°F | n/a°F | n/a |
| July | n/a°F | n/a°F | n/a°F | n/a |
| August | n/a°F | n/a°F | n/a°F | n/a |
| September | n/a°F | n/a°F | n/a°F | n/a |
| October | n/a°F | n/a°F | n/a°F | n/a |
| November | n/a°F | n/a°F | n/a°F | n/a |
| December | n/a°F | n/a°F | n/a°F | n/a |
| Index | Sula | Montana | National |
| Air quality index | 20 | 34 | 42 |
| Pollution index | 848,303 | 834,473 | 2,726,193 |
| Measurement | Total |
| Days measured | 363 |
| Days with good air quality | 319 |
| Days with moderate air quality | 44 |
| Days w/ poor A.Q. for sensitive groups | 0 |
| Days with unhealthy air quality | 0 |
| Pollutant | Total |
| Arsenic | 0.000% |
| Benzene | 0.020% |
| Carbon Tetrachloride | 0.002% |
| Lead | 0.010% |
| Mercury | 0.000% |
| City | Population | Air Quality Index | National Avg. |
| Conner, MT | 98 | 40 | 20.0% |
| Darby, MT | 706 | 40 | 20.0% |
| Sula, MT | 81 | 20 | 60.0% |
| City | Population | Air Quality Index | National Avg. |
| Hope, AK | 81 | 31 | 38.0% |
| Daisy, AR | 81 | 32 | 36.0% |
| Horseshoe Beach, FL | 81 | 35 | 30.0% |
| Numa, IA | 81 | 39 | 22.0% |
| Old Ripley, IL | 81 | 54 | 8.0% |
| Sula, MT | 81 | 20 | 60.0% |