| Month | Temp. (min) | Temp. (max) | Temp. (avg) | Precipitation |
| January | 13°F | 34°F | 23°F | 0.3" |
| February | 14°F | 36°F | 24°F | 0.3" |
| March | 21°F | 46°F | 32°F | 0.3" |
| April | 29°F | 56°F | 41°F | 1.1" |
| May | 36°F | 65°F | 50°F | 1.2" |
| June | 44°F | 74°F | 59°F | 2.5" |
| July | 49°F | 85°F | 67°F | 0.9" |
| August | 48°F | 83°F | 65°F | 0.8" |
| September | 41°F | 72°F | 55°F | 1.1" |
| October | 32°F | 58°F | 44°F | 0.6" |
| November | 20°F | 43°F | 30°F | 0.5" |
| December | 11°F | 32°F | 21°F | 0.2" |
| Index | Dupuyer | 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. |
| Bynum, MT | 25 | 21 | 58.0% |
| Valier, MT | 546 | 21 | 58.0% |
| Dupuyer, MT | 100 | 21 | 58.0% |
| City | Population | Air Quality Index | National Avg. |
| Kasaan, AK | 100 | 20 | 60.0% |
| Kaka, AZ | 100 | 74 | 48.0% |
| Cherokee, CA | 100 | 46 | 8.0% |
| Round Mountain, CA | 100 | 42 | 16.0% |
| Rutherford, CA | 100 | 35 | 30.0% |
| Dupuyer, MT | 100 | 21 | 58.0% |
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