| Month | Temp. (min) | Temp. (max) | Temp. (avg) | Precipitation |
| January | 9°F | 25°F | 17°F | 1.4" |
| February | 11°F | 28°F | 19°F | 2.3" |
| March | 26°F | 43°F | 33°F | 3.6" |
| April | 38°F | 59°F | 47°F | 5.8" |
| May | 49°F | 72°F | 59°F | 5.8" |
| June | 60°F | 80°F | 69°F | 7.3" |
| July | 63°F | 83°F | 73°F | 7.5" |
| August | 60°F | 80°F | 69°F | 7.2" |
| September | 52°F | 75°F | 62°F | 5.8" |
| October | 40°F | 60°F | 49°F | 6.8" |
| November | 27°F | 46°F | 35°F | 2.4" |
| December | 13°F | 29°F | 21°F | 2.9" |
| Index | Mountain Lake | Minnesota | National |
| Air quality index | 32 | 35 | 42 |
| Pollution index | 568,450 | 1,854,519 | 2,726,193 |
| Measurement | Total |
| Days measured | 362 |
| Days with good air quality | 327 |
| Days with moderate air quality | 35 |
| Days w/ poor A.Q. for sensitive groups | 0 |
| Days with unhealthy air quality | 0 |
| Pollutant | Total |
| Arsenic | 0.001% |
| Benzene | 0.020% |
| Carbon Tetrachloride | 0.001% |
| Lead | 0.002% |
| Mercury | 0.000% |
| City | Population | Air Quality Index | National Avg. |
| Comfrey, MN | 343 | 32 | 36.0% |
| Jeffers, MN | 353 | 32 | 36.0% |
| Odin, MN | 137 | 32 | 36.0% |
| Darfur, MN | 73 | 32 | 36.0% |
| Wilder, MN | 38 | 32 | 36.0% |
| Mountain Lake, MN | 2,083 | 32 | 36.0% |
| City | Population | Air Quality Index | National Avg. |
| Hoschton, GA | 2,083 | 37 | 26.0% |
| Harrison, MI | 2,083 | 36 | 28.0% |
| Upton, QC | 2,083 | n/a | |
| Steep Falls, ME | 2,082 | 40 | 20.0% |
| Winsted, MN | 2,084 | 46 | 8.0% |
| Mountain Lake, MN | 2,083 | 32 | 36.0% |