| Month | Temp. (min) | Temp. (max) | Temp. (avg) | Precipitation |
| January | 16°F | 33°F | 25°F | 1.8" |
| February | 15°F | 34°F | 25°F | 1.6" |
| March | 26°F | 47°F | 36°F | 2.4" |
| April | 36°F | 61°F | 48°F | 3.4" |
| May | 46°F | 72°F | 59°F | 3.8" |
| June | 54°F | 80°F | 68°F | 3.7" |
| July | 58°F | 84°F | 72°F | 3.2" |
| August | 57°F | 82°F | 70°F | 2.7" |
| September | 50°F | 76°F | 62°F | 2.4" |
| October | 40°F | 63°F | 51°F | 2.5" |
| November | 29°F | 50°F | 40°F | 2.1" |
| December | 22°F | 38°F | 30°F | 1.9" |
| Index | Milan | Michigan | National |
| Air quality index | 40 | 69 | 42 |
| Pollution index | 1,741,370 | 4,161,606 | 2,726,193 |
| Measurement | Total |
| Days measured | 365 |
| Days with good air quality | 292 |
| Days with moderate air quality | 73 |
| 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 | 0.002% |
| Lead | 0.010% |
| Mercury | 0.000% |
| City | Population | Air Quality Index | National Avg. |
| Petersburg, MI | 1,220 | 1 | 98.0% |
| South Monroe, MI | 6,359 | 1 | 98.0% |
| Dundee, MI | 4,560 | 1 | 98.0% |
| Maybee, MI | 634 | 1 | 98.0% |
| West Monroe, MI | 3,359 | 1 | 98.0% |
| Milan, MI | 6,205 | 40 | 20.0% |
| City | Population | Air Quality Index | National Avg. |
| Pontotoc, MS | 6,205 | 39 | 22.0% |
| Otis Orchards-East Farms, WA | 6,206 | 43 | 14.0% |
| Kodiak, AK | 6,198 | 31 | 38.0% |
| East Pasadena, CA | 6,198 | 72 | 44.0% |
| Bensley, VA | 6,198 | 44 | 12.0% |
| Milan, MI | 6,205 | 40 | 20.0% |