| Month | Temp. (min) | Temp. (max) | Temp. (avg) | Precipitation |
| January | 19°F | 32°F | 25°F | 2.7" |
| February | 18°F | 29°F | 23°F | 2.8" |
| March | 29°F | 44°F | 35°F | 3.4" |
| April | 37°F | 55°F | 45°F | 4.5" |
| May | 47°F | 66°F | 56°F | 3.3" |
| June | 61°F | 79°F | 70°F | 7.1" |
| July | 63°F | 81°F | 72°F | 2.8" |
| August | 65°F | 80°F | 72°F | 12.6" |
| September | 58°F | 76°F | 66°F | 4.6" |
| October | 48°F | 64°F | 55°F | 4.5" |
| November | 33°F | 48°F | 40°F | 4.1" |
| December | 18°F | 30°F | 25°F | 2.6" |
| Index | Mount Pleasant | Wisconsin | National |
| Air quality index | 39 | 69 | 42 |
| Pollution index | 3,131,700 | 2,842,418 | 2,726,193 |
| Measurement | Total |
| Days measured | 203 |
| Days with good air quality | 174 |
| Days with moderate air quality | 28 |
| Days w/ poor A.Q. for sensitive groups | 1 |
| Days with unhealthy air quality | 0 |
| Pollutant | Total |
| Arsenic | 0.010% |
| Benzene | 0.030% |
| Carbon Tetrachloride | 0.010% |
| Lead | 0.004% |
| Mercury | 0.360% |
| City | Population | Air Quality Index | National Avg. |
| Paddock Lake, WI | 3,136 | 39 | 22.0% |
| Elmwood Park, WI | 498 | 39 | 22.0% |
| Wind Point, WI | 1,904 | 39 | 22.0% |
| Somers, WI | 8,564 | 39 | 22.0% |
| Wind Lake, WI | 5,617 | 39 | 22.0% |
| Mount Pleasant, WI | 27,676 | 39 | 22.0% |
| City | Population | Air Quality Index | National Avg. |
| Lindenhurst, NY | 27,681 | 51 | 2.0% |
| New Lenox, IL | 27,687 | 55 | 10.0% |
| Maryland Heights, MO | 27,688 | 54 | 8.0% |
| West Linn, OR | 27,690 | 38 | 24.0% |
| Florence, AZ | 27,692 | 74 | 48.0% |
| Mount Pleasant, WI | 27,676 | 39 | 22.0% |