| Month | Temp. (min) | Temp. (max) | Temp. (avg) | Precipitation |
| January | 23°F | 43°F | 32°F | 3.2" |
| February | 23°F | 44°F | 33°F | 2.5" |
| March | 32°F | 55°F | 43°F | 4.4" |
| April | 41°F | 68°F | 54°F | 4.0" |
| May | 49°F | 73°F | 61°F | 4.7" |
| June | 57°F | 80°F | 68°F | 4.8" |
| July | 61°F | 82°F | 71°F | 5.3" |
| August | 60°F | 81°F | 70°F | 3.9" |
| September | 54°F | 76°F | 64°F | 2.8" |
| October | 43°F | 66°F | 54°F | 3.5" |
| November | 33°F | 56°F | 44°F | 2.5" |
| December | 27°F | 46°F | 36°F | 4.0" |
| Index | Kopperston | West Virginia | National |
| Air quality index | 295 | 126 | 42 |
| Pollution index | 655,580 | 1,996,538 | 2,726,193 |
| Measurement | Total |
| Days measured | 120 |
| Days with good air quality | 106 |
| Days with moderate air quality | 14 |
| Days w/ poor A.Q. for sensitive groups | |
| Days with unhealthy air quality |
| Pollutant | Total |
| Arsenic | 0.100% |
| Benzene | 0.010% |
| Carbon Tetrachloride | 0.003% |
| Lead | 0.010% |
| Mercury | 0.005% |
| City | Population | Air Quality Index | National Avg. |
| Brenton, WV | 110 | 295 | 490.0% |
| Matheny, WV | 155 | 295 | 490.0% |
| Corinne, WV | 103 | 295 | 490.0% |
| New Richmond, WV | 299 | 295 | 490.0% |
| Glen Fork, WV | 415 | 295 | 490.0% |
| Kopperston, WV | 424 | 295 | 490.0% |
| City | Population | Air Quality Index | National Avg. |
| Hammondville, AL | 424 | 39 | 22.0% |
| Desert Shores, CA | 424 | 58 | 16.0% |
| Union, IA | 424 | 37 | 26.0% |
| Deary, ID | 424 | 10 | 80.0% |
| Hazleton, IN | 424 | 36 | 28.0% |
| Kopperston, WV | 424 | 295 | 490.0% |