| Month | Temp. (min) | Temp. (max) | Temp. (avg) | Precipitation |
| January | 18°F | 34°F | 26°F | 2.9" |
| February | 20°F | 38°F | 28°F | 2.9" |
| March | 29°F | 50°F | 38°F | 3.4" |
| April | 39°F | 63°F | 50°F | 4.7" |
| May | 50°F | 74°F | 62°F | 4.8" |
| June | 58°F | 81°F | 69°F | 5.2" |
| July | 62°F | 84°F | 73°F | 3.8" |
| August | 60°F | 82°F | 71°F | 3.0" |
| September | 54°F | 77°F | 65°F | 3.3" |
| October | 44°F | 65°F | 54°F | 3.6" |
| November | 33°F | 53°F | 42°F | 3.4" |
| December | 25°F | 40°F | 32°F | 3.3" |
| Index | Greenwich | Ohio | National |
| Air quality index | 41 | 40 | 42 |
| Pollution index | 2,498,190 | 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 | 0.004% |
| Lead | 0.003% |
| Mercury | 0.001% |
| City | Population | Air Quality Index | National Avg. |
| Monroeville, OH | 1,314 | 40 | 20.0% |
| Tiro, OH | 219 | 41 | 18.0% |
| Plymouth, OH | 1,607 | 41 | 18.0% |
| Holiday Lakes, OH | 647 | 41 | 18.0% |
| Willard, OH | 6,028 | 41 | 18.0% |
| Greenwich, OH | 1,489 | 41 | 18.0% |
| City | Population | Air Quality Index | National Avg. |
| Herscher, IL | 1,489 | 0 | 100.0% |
| Ness City, KS | 1,489 | 15 | 70.0% |
| Thompson Falls, MT | 1,489 | 37 | 26.0% |
| La Huerta, NM | 1,489 | 47 | 6.0% |
| New Fairview, TX | 1,489 | 51 | 2.0% |
| Greenwich, OH | 1,489 | 41 | 18.0% |
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