| Month | Temp. (min) | Temp. (max) | Temp. (avg) | Precipitation |
| January | 5°F | 22°F | 14°F | 0.2" |
| February | 5°F | 25°F | 15°F | 0.8" |
| March | 18°F | 39°F | 28°F | 2.3" |
| April | 31°F | 53°F | 41°F | 2.0" |
| May | 42°F | 66°F | 53°F | 3.1" |
| June | 52°F | 74°F | 62°F | 5.0" |
| July | 55°F | 79°F | 67°F | 3.0" |
| August | 53°F | 76°F | 64°F | 4.0" |
| September | 46°F | 69°F | 57°F | 2.7" |
| October | 35°F | 55°F | 45°F | 2.2" |
| November | 24°F | 41°F | 32°F | 1.0" |
| December | 11°F | 26°F | 19°F | 0.7" |
| Index | Birnamwood | Wisconsin | National |
| Air quality index | 34 | 69 | 42 |
| Pollution index | 1,286,800 | 2,842,418 | 2,726,193 |
| Measurement | Total |
| Days measured | 205 |
| Days with good air quality | 196 |
| Days with moderate air quality | 9 |
| Days w/ poor A.Q. for sensitive groups | 0 |
| Days with unhealthy air quality | 0 |
| Pollutant | Total |
| Arsenic | 0.001% |
| Benzene | 0.020% |
| Carbon Tetrachloride | 0.001% |
| Lead | 0.000% |
| Mercury | 0.001% |
| City | Population | Air Quality Index | National Avg. |
| Antigo, WI | 7,941 | 34 | 32.0% |
| Bowler, WI | 356 | 34 | 32.0% |
| Hatley, WI | 571 | 34 | 32.0% |
| Eland, WI | 226 | 34 | 32.0% |
| Mattoon, WI | 426 | 34 | 32.0% |
| Birnamwood, WI | 793 | 34 | 32.0% |
| City | Population | Air Quality Index | National Avg. |
| Kivalina, AK | 793 | 38 | 24.0% |
| Tampico, IL | 793 | 42 | 16.0% |
| Troy, KS | 793 | 43 | 14.0% |
| Galena, MO | 793 | 18 | 64.0% |
| Oriskany Falls, NY | 793 | 27 | 46.0% |
| Birnamwood, WI | 793 | 34 | 32.0% |