| Month | Temp. (min) | Temp. (max) | Temp. (avg) | Precipitation |
| January | 15°F | 34°F | 25°F | 3.1" |
| February | 16°F | 36°F | 25°F | 3.1" |
| March | 29°F | 50°F | 38°F | 4.2" |
| April | 40°F | 65°F | 52°F | 7.0" |
| May | 50°F | 74°F | 62°F | 5.1" |
| June | 60°F | 81°F | 70°F | 5.3" |
| July | 61°F | 81°F | 71°F | 4.8" |
| August | 59°F | 81°F | 69°F | 8.6" |
| September | 52°F | 78°F | 64°F | 5.3" |
| October | 43°F | 67°F | 54°F | 7.0" |
| November | 31°F | 51°F | 40°F | 4.4" |
| December | 26°F | 42°F | 34°F | 4.5" |
| Index | Marysville | Ohio | National |
| Air quality index | 46 | 40 | 42 |
| Pollution index | 1,015,950 | 4,472,386 | 2,726,193 |
| Measurement | Total |
| Days measured | 365 |
| Days with good air quality | 237 |
| Days with moderate air quality | 127 |
| Days w/ poor A.Q. for sensitive groups | 1 |
| Days with unhealthy air quality | 0 |
| Pollutant | Total |
| Arsenic | 0.001% |
| Benzene | 0.010% |
| Carbon Tetrachloride | 0.002% |
| Lead | 0.010% |
| Mercury | 0.000% |
| City | Population | Air Quality Index | National Avg. |
| West Mansfield, OH | 749 | 45 | 10.0% |
| Mutual, OH | 84 | 45 | 10.0% |
| North Lewisburg, OH | 1,633 | 45 | 10.0% |
| East Liberty, OH | 402 | 45 | 10.0% |
| Milford Center, OH | 1,038 | 45 | 10.0% |
| Marysville, OH | 25,078 | 46 | 8.0% |
| City | Population | Air Quality Index | National Avg. |
| Farmington, UT | 25,076 | 51 | 2.0% |
| Palm River-Clair Mel, FL | 25,085 | 43 | 14.0% |
| Ridgeland, MS | 25,070 | 44 | 12.0% |
| Collinsville, IL | 25,068 | 54 | 8.0% |
| Herndon, VA | 25,119 | 47 | 6.0% |
| Marysville, OH | 25,078 | 46 | 8.0% |