| Month | Temp. (min) | Temp. (max) | Temp. (avg) | Precipitation |
| January | 11°F | 30°F | 20°F | 1.5" |
| February | 13°F | 33°F | 23°F | 1.5" |
| March | 24°F | 47°F | 35°F | 2.6" |
| April | 35°F | 61°F | 48°F | 4.4" |
| May | 46°F | 73°F | 59°F | 4.0" |
| June | 57°F | 81°F | 69°F | 5.9" |
| July | 60°F | 85°F | 73°F | 4.9" |
| August | 59°F | 83°F | 71°F | 4.8" |
| September | 51°F | 77°F | 63°F | 3.5" |
| October | 40°F | 63°F | 51°F | 3.2" |
| November | 28°F | 49°F | 38°F | 2.1" |
| December | 17°F | 34°F | 25°F | 2.3" |
| Index | Rio | Wisconsin | National |
| Air quality index | 40 | 69 | 42 |
| Pollution index | 3,153,950 | 2,842,418 | 2,726,193 |
| Measurement | Total |
| Days measured | 365 |
| Days with good air quality | 297 |
| Days with moderate air quality | 67 |
| Days w/ poor A.Q. for sensitive groups | 1 |
| Days with unhealthy air quality | 0 |
| Pollutant | Total |
| Arsenic | 0.010% |
| Benzene | 0.050% |
| Carbon Tetrachloride | 0.002% |
| Lead | 0.002% |
| Mercury | 0.150% |
| City | Population | Air Quality Index | National Avg. |
| Lodi, WI | 3,180 | 35 | 30.0% |
| Pardeeville, WI | 2,114 | 35 | 30.0% |
| Portage, WI | 10,657 | 35 | 30.0% |
| Wyocena, WI | 752 | 35 | 30.0% |
| Poynette, WI | 2,559 | 35 | 30.0% |
| Rio, WI | 1,070 | 40 | 20.0% |
| City | Population | Air Quality Index | National Avg. |
| Manassa, CO | 1,070 | 15 | 70.0% |
| Masaryktown, FL | 1,070 | 30 | 40.0% |
| Winfield, IA | 1,070 | 32 | 36.0% |
| Ironville, KY | 1,070 | 42 | 16.0% |
| Newellton, LA | 1,070 | 34 | 32.0% |
| Rio, WI | 1,070 | 40 | 20.0% |