| Month | Temp. (min) | Temp. (max) | Temp. (avg) | Precipitation |
| January | 9°F | 26°F | 18°F | 2.0" |
| February | 11°F | 30°F | 20°F | 1.8" |
| March | 24°F | 44°F | 34°F | 4.2" |
| April | 35°F | 58°F | 46°F | 6.4" |
| May | 45°F | 70°F | 58°F | 6.5" |
| June | 55°F | 78°F | 67°F | 8.0" |
| July | 58°F | 82°F | 71°F | 8.5" |
| August | 56°F | 80°F | 68°F | 8.2" |
| September | 48°F | 73°F | 60°F | 8.3" |
| October | 38°F | 60°F | 48°F | 5.1" |
| November | 27°F | 46°F | 36°F | 3.3" |
| December | 15°F | 31°F | 23°F | 3.0" |
| Index | Hillsboro | Wisconsin | National |
| Air quality index | 35 | 69 | 42 |
| Pollution index | 367,008 | 2,842,418 | 2,726,193 |
| Measurement | Total |
| Days measured | 365 |
| Days with good air quality | 311 |
| Days with moderate air quality | 53 |
| Days w/ poor A.Q. for sensitive groups | 1 |
| Days with unhealthy air quality | 0 |
| Pollutant | Total |
| Arsenic | 0.000% |
| Benzene | 0.005% |
| Carbon Tetrachloride | 0.000% |
| Lead | 0.002% |
| Mercury | 0.000% |
| City | Population | Air Quality Index | National Avg. |
| La Valle, WI | 377 | 35 | 30.0% |
| Union Center, WI | 224 | 35 | 30.0% |
| Kendall, WI | 486 | 35 | 30.0% |
| Lime Ridge, WI | 191 | 35 | 30.0% |
| Norwalk, WI | 740 | 35 | 30.0% |
| Hillsboro, WI | 1,392 | 35 | 30.0% |
| City | Population | Air Quality Index | National Avg. |
| Macpherson-Grizzly Valley, YT | 1,392 | n/a | |
| Cactus Flats, AZ | 1,391 | 47 | 6.0% |
| Pierce, CO | 1,391 | 45 | 10.0% |
| Clarksville, IA | 1,391 | 39 | 22.0% |
| Starbuck, MN | 1,393 | 32 | 36.0% |
| Hillsboro, WI | 1,392 | 35 | 30.0% |