| Month | Temp. (min) | Temp. (max) | Temp. (avg) | Precipitation |
| January | 13°F | 26°F | 19°F | 0.1" |
| February | 13°F | 28°F | 20°F | 0.0" |
| March | 26°F | 41°F | 33°F | 0.4" |
| April | 37°F | 55°F | 45°F | 0.9" |
| May | 48°F | 68°F | 57°F | 1.0" |
| June | 58°F | 76°F | 67°F | 1.7" |
| July | 62°F | 81°F | 71°F | 0.4" |
| August | 61°F | 78°F | 69°F | 0.2" |
| September | 53°F | 71°F | 61°F | 1.0" |
| October | 42°F | 58°F | 49°F | 0.7" |
| November | 30°F | 44°F | 37°F | 0.2" |
| December | 18°F | 30°F | 24°F | 0.2" |
| Index | Harrison | Wisconsin | National |
| Air quality index | 37 | 69 | 42 |
| Pollution index | 1,300,960 | 2,842,418 | 2,726,193 |
| Measurement | Total |
| Days measured | 365 |
| Days with good air quality | 304 |
| Days with moderate air quality | 59 |
| Days w/ poor A.Q. for sensitive groups | 2 |
| Days with unhealthy air quality | 0 |
| Pollutant | Total |
| Arsenic | 0.001% |
| Benzene | 0.020% |
| Carbon Tetrachloride | 0.001% |
| Lead | 0.001% |
| Mercury | 0.001% |
| City | Population | Air Quality Index | National Avg. |
| New Holstein, WI | 3,236 | 36 | 28.0% |
| Oshkosh, WI | 69,404 | 36 | 28.0% |
| Appleton, WI | 76,203 | 37 | 26.0% |
| Combined Locks, WI | 3,672 | 37 | 26.0% |
| Brillion, WI | 3,212 | 37 | 26.0% |
| Harrison, WI | 12,579 | 37 | 26.0% |
| City | Population | Air Quality Index | National Avg. |
| Holly Hill, FL | 12,579 | 31 | 38.0% |
| Princeton, TX | 12,578 | 51 | 2.0% |
| Mays Chapel, MD | 12,573 | 46 | 8.0% |
| Ottawa, KS | 12,572 | 41 | 18.0% |
| Santaquin, UT | 12,586 | 46 | 8.0% |
| Harrison, WI | 12,579 | 37 | 26.0% |