| Month | Temp. (min) | Temp. (max) | Temp. (avg) | Precipitation |
| January | 21°F | 38°F | 29°F | 4.7" |
| February | 22°F | 40°F | 30°F | 4.9" |
| March | 33°F | 54°F | 42°F | 6.6" |
| April | 42°F | 67°F | 54°F | 6.8" |
| May | 52°F | 75°F | 64°F | 6.8" |
| June | 61°F | 83°F | 72°F | 7.3" |
| July | 64°F | 85°F | 75°F | 8.6" |
| August | 63°F | 85°F | 74°F | 6.8" |
| September | 56°F | 79°F | 66°F | 6.6" |
| October | 44°F | 67°F | 55°F | 6.5" |
| November | 33°F | 55°F | 43°F | 6.1" |
| December | 27°F | 43°F | 34°F | 6.1" |
| Index | Grafton Hill | Dayton | Ohio |
| Air quality index | 47 | 47 | 40 |
| Pollution index | 11,539,300 | 11,539,300 | 4,472,386 |
| Measurement | Total |
| Days measured | 365 |
| Days with good air quality | 213 |
| Days with moderate air quality | 152 |
| Days w/ poor A.Q. for sensitive groups | 0 |
| Days with unhealthy air quality | 0 |
| Pollutant | Total |
| Arsenic | 0.210% |
| Benzene | 0.110% |
| Carbon Tetrachloride | 0.060% |
| Lead | 0.110% |
| Mercury | 0.050% |
| City | Population | Air Quality Index | National Avg. |
| Spring Valley, OH | 855 | 43 | 14.0% |
| New Burlington, OH | 4,526 | 43 | 14.0% |
| New Carlisle, OH | 5,577 | 45 | 10.0% |
| Holiday Valley, OH | 1,573 | 45 | 10.0% |
| Enon, OH | 2,517 | 45 | 10.0% |
| Dayton, OH | 140,444 | 47 | 6.0% |
| City | Population | Air Quality Index | National Avg. |
| Miramar, FL | 140,479 | 41 | 18.0% |
| Cambridge, ON | 140,221 | n/a | |
| St. Catharines, ON | 140,913 | n/a | |
| Fullerton, CA | 141,061 | 72 | 44.0% |
| Denton, TX | 139,734 | 51 | 2.0% |
| Dayton, OH | 140,444 | 47 | 6.0% |
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