| Month | Temp. (min) | Temp. (max) | Temp. (avg) | Precipitation |
| January | 20°F | 36°F | 28°F | 2.2" |
| February | 20°F | 36°F | 28°F | 2.2" |
| March | 30°F | 49°F | 38°F | 2.9" |
| April | 40°F | 62°F | 50°F | 3.3" |
| May | 51°F | 73°F | 62°F | 3.9" |
| June | 60°F | 81°F | 70°F | 4.7" |
| July | 63°F | 84°F | 73°F | 3.8" |
| August | 61°F | 82°F | 71°F | 3.7" |
| September | 55°F | 77°F | 65°F | 3.9" |
| October | 45°F | 65°F | 54°F | 4.2" |
| November | 35°F | 53°F | 43°F | 3.0" |
| December | 27°F | 41°F | 33°F | 3.0" |
| Index | Grafton | Ohio | National |
| Air quality index | 50 | 40 | 42 |
| Pollution index | 9,912,140 | 4,472,386 | 2,726,193 |
| Measurement | Total |
| Days measured | 365 |
| Days with good air quality | 185 |
| Days with moderate air quality | 173 |
| Days w/ poor A.Q. for sensitive groups | 7 |
| Days with unhealthy air quality | 0 |
| Pollutant | Total |
| Arsenic | 0.120% |
| Benzene | 0.080% |
| Carbon Tetrachloride | 0.020% |
| Lead | 0.440% |
| Mercury | 0.260% |
| City | Population | Air Quality Index | National Avg. |
| Medina, OH | 26,667 | 43 | 14.0% |
| Chippewa Lake, OH | 772 | 43 | 14.0% |
| Spencer, OH | 707 | 43 | 14.0% |
| Sheffield Lake, OH | 9,354 | 50 | = 100 |
| Eaton Estates, OH | 1,234 | 50 | = 100 |
| Grafton, OH | 6,168 | 50 | = 100 |
| City | Population | Air Quality Index | National Avg. |
| Northville, MI | 6,168 | 40 | 20.0% |
| Mulvane, KS | 6,166 | 40 | 20.0% |
| Ocean City, FL | 6,170 | 31 | 38.0% |
| Gilbertsville, PA | 6,170 | 42 | 16.0% |
| Shaw Heights, CO | 6,165 | 58 | 16.0% |
| Grafton, OH | 6,168 | 50 | = 100 |