| Month | Temp. (min) | Temp. (max) | Temp. (avg) | Precipitation |
| January | 24°F | 35°F | 29°F | 4.1" |
| February | 26°F | 40°F | 32°F | 2.4" |
| March | 31°F | 49°F | 39°F | 3.4" |
| April | 36°F | 58°F | 45°F | 2.8" |
| May | 43°F | 69°F | 55°F | 2.9" |
| June | 50°F | 75°F | 61°F | 6.5" |
| July | 55°F | 87°F | 70°F | 3.1" |
| August | 54°F | 86°F | 69°F | 3.1" |
| September | 47°F | 76°F | 60°F | 2.9" |
| October | 38°F | 59°F | 47°F | 4.0" |
| November | 31°F | 44°F | 37°F | 3.4" |
| December | 23°F | 34°F | 28°F | 3.9" |
| Index | St. Maries | Idaho | National |
| Air quality index | 10 | 32 | 42 |
| Pollution index | 1,107,360 | 2,063,710 | 2,726,193 |
| Measurement | Total |
| Days measured | 350 |
| Days with good air quality | 350 |
| Days with moderate air quality | 0 |
| Days w/ poor A.Q. for sensitive groups | 0 |
| Days with unhealthy air quality | 0 |
| Pollutant | Total |
| Arsenic | 0.001% |
| Benzene | 0.010% |
| Carbon Tetrachloride | 0.000% |
| Lead | 0.004% |
| Mercury | 0.000% |
| City | Population | Air Quality Index | National Avg. |
| Plummer, ID | 1,027 | 43 | 14.0% |
| Conkling Park, ID | 131 | 43 | 14.0% |
| Rockford Bay, ID | 362 | 43 | 14.0% |
| Harrison, ID | 287 | 43 | 14.0% |
| Parkline, ID | 35 | 43 | 14.0% |
| St. Maries, ID | 3,338 | 10 | 80.0% |
| City | Population | Air Quality Index | National Avg. |
| San Miguel, CA | 3,337 | 40 | 20.0% |
| Avon, NY | 3,337 | 37 | 26.0% |
| Mount Shasta, CA | 3,339 | 42 | 16.0% |
| Holton, KS | 3,336 | 41 | 18.0% |
| Saint-Ferréol-les-Neiges, QC | 3,336 | n/a | |
| St. Maries, ID | 3,338 | 10 | 80.0% |