| Month | Temp. (min) | Temp. (max) | Temp. (avg) | Precipitation |
| January | 13°F | 33°F | 22°F | 0.4" |
| February | 15°F | 37°F | 25°F | 0.7" |
| March | 29°F | 54°F | 40°F | 1.4" |
| April | 39°F | 66°F | 51°F | 3.5" |
| May | 51°F | 77°F | 63°F | 4.0" |
| June | 62°F | 86°F | 73°F | 5.1" |
| July | 65°F | 89°F | 76°F | 3.0" |
| August | 62°F | 85°F | 73°F | 4.9" |
| September | 53°F | 79°F | 65°F | 3.9" |
| October | 41°F | 67°F | 52°F | 2.4" |
| November | 28°F | 52°F | 39°F | 0.9" |
| December | 16°F | 36°F | 25°F | 1.2" |
| Index | Herman | Nebraska | National |
| Air quality index | 40 | 86 | 42 |
| Pollution index | 238,372 | 590,627 | 2,726,193 |
| Measurement | Total |
| Days measured | 365 |
| Days with good air quality | 283 |
| Days with moderate air quality | 82 |
| Days w/ poor A.Q. for sensitive groups | 0 |
| Days with unhealthy air quality | 0 |
| Pollutant | Total |
| Arsenic | 0.000% |
| Benzene | 0.004% |
| Carbon Tetrachloride | 0.001% |
| Lead | 0.000% |
| Mercury | 0.000% |
| City | Population | Air Quality Index | National Avg. |
| California Junction, IA | 41 | 40 | 20.0% |
| River Sioux, IA | 41 | 40 | 20.0% |
| Tekamah, NE | 1,791 | 40 | 20.0% |
| Blair, NE | 8,063 | 40 | 20.0% |
| Modale, IA | 307 | 40 | 20.0% |
| Herman, NE | 485 | 40 | 20.0% |
| City | Population | Air Quality Index | National Avg. |
| Black, AL | 485 | 35 | 30.0% |
| Concow, CA | 485 | 46 | 8.0% |
| Creal Springs, IL | 485 | 44 | 12.0% |
| Davis, IL | 485 | 42 | 16.0% |
| Sharpsburg, KY | 485 | 42 | 16.0% |
| Herman, NE | 485 | 40 | 20.0% |