| Month | Temp. (min) | Temp. (max) | Temp. (avg) | Precipitation |
| January | 5°F | 23°F | 13°F | 0.6" |
| February | 7°F | 27°F | 16°F | 0.8" |
| March | 21°F | 42°F | 31°F | 1.5" |
| April | 34°F | 57°F | 45°F | 2.7" |
| May | 45°F | 70°F | 57°F | 4.1" |
| June | 56°F | 79°F | 67°F | 4.3" |
| July | 60°F | 85°F | 72°F | 3.4" |
| August | 57°F | 81°F | 69°F | 4.9" |
| September | 50°F | 74°F | 61°F | 3.5" |
| October | 38°F | 58°F | 47°F | 3.4" |
| November | 24°F | 43°F | 33°F | 1.2" |
| December | 10°F | 26°F | 18°F | 1.3" |
| Index | Rockville | Minnesota | National |
| Air quality index | 32 | 35 | 42 |
| Pollution index | 1,174,010 | 1,854,519 | 2,726,193 |
| Measurement | Total |
| Days measured | 344 |
| Days with good air quality | 313 |
| Days with moderate air quality | 31 |
| Days w/ poor A.Q. for sensitive groups | 0 |
| Days with unhealthy air quality | 0 |
| Pollutant | Total |
| Arsenic | 0.002% |
| Benzene | 0.020% |
| Carbon Tetrachloride | 0.000% |
| Lead | 0.001% |
| Mercury | 0.001% |
| City | Population | Air Quality Index | National Avg. |
| Cold Spring, MN | 4,238 | 32 | 36.0% |
| St. Joseph, MN | 7,448 | 32 | 36.0% |
| Watkins, MN | 859 | 32 | 36.0% |
| Annandale, MN | 3,420 | 32 | 36.0% |
| Fairhaven, MN | 397 | 32 | 36.0% |
| Rockville, MN | 2,571 | 32 | 36.0% |
| City | Population | Air Quality Index | National Avg. |
| Lavonia, GA | 2,571 | 41 | 18.0% |
| Abita Springs, LA | 2,571 | 30 | 40.0% |
| West Lafayette, OH | 2,571 | 41 | 18.0% |
| George West, TX | 2,571 | 30 | 40.0% |
| Luxemburg, WI | 2,571 | 36 | 28.0% |
| Rockville, MN | 2,571 | 32 | 36.0% |
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