| Month | Temp. (min) | Temp. (max) | Temp. (avg) | Precipitation |
| January | 12°F | 26°F | 19°F | 2.7" |
| February | 16°F | 31°F | 23°F | 1.6" |
| March | 29°F | 46°F | 37°F | 4.7" |
| April | 38°F | 57°F | 46°F | 5.4" |
| May | 50°F | 71°F | 60°F | 7.0" |
| June | 59°F | 80°F | 69°F | 8.8" |
| July | 65°F | 86°F | 75°F | 10.2" |
| August | 60°F | 82°F | 70°F | 9.0" |
| September | 50°F | 70°F | 59°F | 5.6" |
| October | 42°F | 61°F | 50°F | 3.8" |
| November | 30°F | 47°F | 37°F | 2.8" |
| December | 18°F | 30°F | 24°F | 2.5" |
| Index | Viola | Wisconsin | National |
| Air quality index | 35 | 69 | 42 |
| Pollution index | 1,068,810 | 2,842,418 | 2,726,193 |
| Measurement | Total |
| Days measured | 365 |
| Days with good air quality | 310 |
| Days with moderate air quality | 55 |
| Days w/ poor A.Q. for sensitive groups | 0 |
| Days with unhealthy air quality | 0 |
| Pollutant | Total |
| Arsenic | 0.001% |
| Benzene | 0.010% |
| Carbon Tetrachloride | 0.001% |
| Lead | 0.000% |
| Mercury | 0.001% |
| City | Population | Air Quality Index | National Avg. |
| Boaz, WI | 131 | 35 | 30.0% |
| Ontario, WI | 496 | 35 | 30.0% |
| Westby, WI | 2,449 | 35 | 30.0% |
| Gays Mills, WI | 492 | 35 | 30.0% |
| Readstown, WI | 430 | 35 | 30.0% |
| Viola, WI | 765 | 35 | 30.0% |
| City | Population | Air Quality Index | National Avg. |
| Plumerville, AR | 765 | 45 | 10.0% |
| Panacea, FL | 765 | 40 | 20.0% |
| Maxwell, IA | 765 | 37 | 26.0% |
| Gray, ME | 765 | 31 | 38.0% |
| Viburnum, MO | 765 | 54 | 8.0% |
| Viola, WI | 765 | 35 | 30.0% |