| Month | Temp. (min) | Temp. (max) | Temp. (avg) | Precipitation |
| January | 10°F | 25°F | 17°F | 0.2" |
| February | 11°F | 28°F | 18°F | 0.3" |
| March | 25°F | 43°F | 33°F | 1.1" |
| April | 38°F | 59°F | 47°F | 2.2" |
| May | 50°F | 69°F | 58°F | 1.3" |
| June | 61°F | 82°F | 70°F | 1.9" |
| July | 64°F | 84°F | 74°F | 0.9" |
| August | 60°F | 80°F | 70°F | 8.9" |
| September | 55°F | 76°F | 64°F | 11.0" |
| October | 44°F | 62°F | 51°F | 9.0" |
| November | 27°F | 44°F | 34°F | 0.6" |
| December | 11°F | 24°F | 17°F | 1.0" |
| Index | Hanover | Minnesota | National |
| Air quality index | 46 | 35 | 42 |
| Pollution index | 166,775 | 1,854,519 | 2,726,193 |
| Measurement | Total |
| Days measured | 365 |
| Days with good air quality | 214 |
| Days with moderate air quality | 148 |
| Days w/ poor A.Q. for sensitive groups | 2 |
| Days with unhealthy air quality | 1 |
| Pollutant | Total |
| Arsenic | 0.000% |
| Benzene | 0.002% |
| Carbon Tetrachloride | 0.000% |
| Lead | 0.000% |
| Mercury | 0.000% |
| City | Population | Air Quality Index | National Avg. |
| Big Lake, MN | 11,468 | 32 | 36.0% |
| Waverly, MN | 1,550 | 32 | 36.0% |
| Monticello, MN | 14,058 | 32 | 36.0% |
| Buffalo, MN | 16,770 | 32 | 36.0% |
| Big Lake CDP, MN | 390 | 32 | 36.0% |
| Hanover, MN | 3,482 | 46 | 8.0% |
| City | Population | Air Quality Index | National Avg. |
| Rio Dell, CA | 3,481 | 27 | 46.0% |
| Whispering Pines, NC | 3,481 | 29 | 42.0% |
| Palmyra, NY | 3,480 | 37 | 26.0% |
| Fort Branch, IN | 3,484 | 45 | 10.0% |
| Newcastle, WY | 3,484 | 44 | 12.0% |
| Hanover, MN | 3,482 | 46 | 8.0% |