| Month | Temp. (min) | Temp. (max) | Temp. (avg) | Precipitation |
| January | 11°F | 28°F | 19°F | 1.1" |
| February | 13°F | 31°F | 21°F | 1.0" |
| March | 26°F | 46°F | 35°F | 2.0" |
| April | 39°F | 61°F | 49°F | 4.2" |
| May | 50°F | 72°F | 60°F | 4.7" |
| June | 60°F | 82°F | 70°F | 5.7" |
| July | 65°F | 86°F | 75°F | 4.9" |
| August | 62°F | 83°F | 72°F | 4.4" |
| September | 55°F | 76°F | 64°F | 3.9" |
| October | 43°F | 62°F | 52°F | 3.2" |
| November | 31°F | 48°F | 39°F | 1.3" |
| December | 17°F | 31°F | 24°F | 2.1" |
| Index | Onalaska | Wisconsin | National |
| Air quality index | 35 | 69 | 42 |
| Pollution index | 3,548,710 | 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 | 0.010% |
| Benzene | 0.050% |
| Carbon Tetrachloride | 0.010% |
| Lead | 0.010% |
| Mercury | 0.020% |
| City | Population | Air Quality Index | National Avg. |
| Galesville, WI | 1,628 | 15 | 70.0% |
| Trempealeau, WI | 2,034 | 15 | 70.0% |
| Hokah, MN | 592 | 35 | 30.0% |
| Coon Valley, WI | 937 | 35 | 30.0% |
| St. Joseph, WI | 593 | 35 | 30.0% |
| Onalaska, WI | 18,814 | 35 | 30.0% |
| City | Population | Air Quality Index | National Avg. |
| Madisonville, KY | 18,801 | 43 | 14.0% |
| Bellwood, IL | 18,799 | 55 | 10.0% |
| Farmington, MO | 18,792 | 54 | 8.0% |
| Alsip, IL | 18,843 | 55 | 10.0% |
| Jacksonville, IL | 18,784 | 40 | 20.0% |
| Onalaska, WI | 18,814 | 35 | 30.0% |
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