| Month | Temp. (min) | Temp. (max) | Temp. (avg) | Precipitation |
| January | 21°F | 36°F | 28°F | 5.3" |
| February | 16°F | 33°F | 24°F | 1.7" |
| March | 28°F | 49°F | 37°F | 4.0" |
| April | 37°F | 59°F | 47°F | 4.8" |
| May | 47°F | 73°F | 59°F | 5.7" |
| June | 58°F | 83°F | 70°F | 2.2" |
| July | 60°F | 83°F | 71°F | 6.1" |
| August | 61°F | 83°F | 71°F | 4.3" |
| September | 51°F | 79°F | 64°F | 2.8" |
| October | 45°F | 66°F | 55°F | 4.0" |
| November | 32°F | 53°F | 42°F | 3.8" |
| December | 23°F | 37°F | 29°F | 3.3" |
| Index | Millersburg | Ohio | National |
| Air quality index | 41 | 40 | 42 |
| Pollution index | 1,256,000 | 4,472,386 | 2,726,193 |
| Measurement | Total |
| Days measured | 245 |
| Days with good air quality | 218 |
| Days with moderate air quality | 27 |
| 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 | 0.000% |
| Lead | 0.010% |
| Mercury | 0.000% |
| City | Population | Air Quality Index | National Avg. |
| Lake Buckhorn, OH | 386 | 41 | 18.0% |
| Gann, OH | 127 | 41 | 18.0% |
| Nellie, OH | 253 | 41 | 18.0% |
| Glenmont, OH | 273 | 41 | 18.0% |
| Nashville, OH | 325 | 41 | 18.0% |
| Millersburg, OH | 3,187 | 41 | 18.0% |
| City | Population | Air Quality Index | National Avg. |
| Surf City, NC | 3,187 | 34 | 32.0% |
| Bethel Acres, OK | 3,187 | 36 | 28.0% |
| Peaceful Valley, WA | 3,187 | 34 | 32.0% |
| Mannford, OK | 3,186 | 45 | 10.0% |
| Annapolis, Subd. D, NS | 3,186 | n/a | |
| Millersburg, OH | 3,187 | 41 | 18.0% |
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