| Month | Temp. (min) | Temp. (max) | Temp. (avg) | Precipitation |
| January | 26°F | 40°F | 33°F | 7.1" |
| February | 20°F | 36°F | 28°F | 3.7" |
| March | 34°F | 53°F | 42°F | 5.4" |
| April | 41°F | 64°F | 52°F | 5.8" |
| May | 50°F | 75°F | 63°F | 4.5" |
| June | 62°F | 84°F | 73°F | 4.7" |
| July | 64°F | 84°F | 74°F | 5.1" |
| August | 66°F | 88°F | 77°F | 5.8" |
| September | 58°F | 81°F | 69°F | 7.4" |
| October | 49°F | 67°F | 58°F | 6.6" |
| November | 34°F | 55°F | 44°F | 9.5" |
| December | 25°F | 39°F | 31°F | 4.6" |
| Index | Corwin | Ohio | National |
| Air quality index | 43 | 40 | 42 |
| Pollution index | 7,300,490 | 4,472,386 | 2,726,193 |
| Measurement | Total |
| Days measured | 244 |
| Days with good air quality | 203 |
| Days with moderate air quality | 41 |
| Days w/ poor A.Q. for sensitive groups | 0 |
| Days with unhealthy air quality | 0 |
| Pollutant | Total |
| Arsenic | 0.520% |
| Benzene | 0.070% |
| Carbon Tetrachloride | 0.040% |
| Lead | 0.240% |
| Mercury | 0.050% |
| City | Population | Air Quality Index | National Avg. |
| Spring Valley, OH | 855 | 43 | 14.0% |
| Harveysburg, OH | 725 | 43 | 14.0% |
| Waynesville, OH | 3,135 | 43 | 14.0% |
| Lebanon, OH | 20,781 | 43 | 14.0% |
| Clarksville, OH | 455 | 43 | 14.0% |
| Corwin, OH | 434 | 43 | 14.0% |
| City | Population | Air Quality Index | National Avg. |
| Rock Mills, AL | 434 | 42 | 16.0% |
| Clay Springs, AZ | 434 | 44 | 12.0% |
| Mesa, CA | 434 | 47 | 6.0% |
| Livermore, IA | 434 | 15 | 70.0% |
| Orient, IA | 434 | 39 | 22.0% |
| Corwin, OH | 434 | 43 | 14.0% |
Here are the best places to live in Ohio
See the best places to live in & around Corwin
10 best cities to buy a new house in Ohio
These are the 10 most affordable cities in Ohio