| Month | Temp. (min) | Temp. (max) | Temp. (avg) | Precipitation |
| January | 22°F | 38°F | 30°F | 3.0" |
| February | 22°F | 40°F | 31°F | 2.8" |
| March | 33°F | 53°F | 42°F | 4.5" |
| April | 43°F | 66°F | 54°F | 4.5" |
| May | 52°F | 75°F | 63°F | 4.1" |
| June | 61°F | 83°F | 72°F | 4.9" |
| July | 63°F | 85°F | 73°F | 4.0" |
| August | 61°F | 84°F | 72°F | 3.3" |
| September | 55°F | 79°F | 66°F | 3.3" |
| October | 44°F | 67°F | 55°F | 4.1" |
| November | 33°F | 55°F | 43°F | 3.3" |
| December | 27°F | 43°F | 34°F | 3.9" |
| Index | West Union | Ohio | National |
| Air quality index | 14 | 40 | 42 |
| Pollution index | 1,306,310 | 4,472,386 | 2,726,193 |
| Measurement | Total |
| Days measured | 365 |
| Days with good air quality | 356 |
| Days with moderate air quality | 9 |
| Days w/ poor A.Q. for sensitive groups | 0 |
| Days with unhealthy air quality | 0 |
| Pollutant | Total |
| Arsenic | 0.010% |
| Benzene | 0.020% |
| Carbon Tetrachloride | 0.002% |
| Lead | 0.290% |
| Mercury | 0.120% |
| City | Population | Air Quality Index | National Avg. |
| Maysville, KY | 9,021 | 14 | 72.0% |
| Rome, OH | 81 | 14 | 72.0% |
| Peebles, OH | 2,235 | 14 | 72.0% |
| Cherry Fork, OH | 62 | 14 | 72.0% |
| Vanceburg, KY | 1,416 | 14 | 72.0% |
| West Union, OH | 3,192 | 14 | 72.0% |
| City | Population | Air Quality Index | National Avg. |
| Sixteen Mile Stand, OH | 3,192 | 54 | 8.0% |
| Saint-Anaclet-de-Lessard, QC | 3,192 | n/a | |
| East Brewton, AL | 3,191 | 41 | 18.0% |
| Henrietta, TX | 3,191 | 26 | 48.0% |
| McSherrystown, PA | 3,193 | 42 | 16.0% |
| West Union, OH | 3,192 | 14 | 72.0% |