| Month | Temp. (min) | Temp. (max) | Temp. (avg) | Precipitation |
| January | 20°F | 36°F | 28°F | 3.1" |
| February | 20°F | 39°F | 29°F | 4.1" |
| March | 32°F | 53°F | 41°F | 6.6" |
| April | 42°F | 66°F | 53°F | 6.2" |
| May | 52°F | 75°F | 63°F | 5.9" |
| June | 61°F | 83°F | 71°F | 7.9" |
| July | 63°F | 84°F | 73°F | 7.6" |
| August | 61°F | 84°F | 72°F | 5.1" |
| September | 54°F | 78°F | 65°F | 6.7" |
| October | 44°F | 67°F | 54°F | 5.4" |
| November | 33°F | 53°F | 42°F | 4.5" |
| December | 26°F | 42°F | 33°F | 5.4" |
| Index | Donnelsville | Ohio | National |
| Air quality index | 45 | 40 | 42 |
| Pollution index | 11,539,300 | 4,472,386 | 2,726,193 |
| Measurement | Total |
| Days measured | 365 |
| Days with good air quality | 220 |
| Days with moderate air quality | 143 |
| Days w/ poor A.Q. for sensitive groups | 2 |
| 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. |
| Wilberforce, OH | 2,508 | 45 | 10.0% |
| New Carlisle, OH | 5,716 | 45 | 10.0% |
| Northridge, OH | 7,500 | 45 | 10.0% |
| St. Paris, OH | 2,209 | 45 | 10.0% |
| Springfield, OH | 60,312 | 45 | 10.0% |
| Donnelsville, OH | 340 | 45 | 10.0% |
| City | Population | Air Quality Index | National Avg. |
| McLain, MS | 340 | 35 | 30.0% |
| Bridgeton, NC | 340 | 0 | 100.0% |
| Willard, NM | 340 | 53 | 6.0% |
| Camp Sherman, OR | 340 | 20 | 60.0% |
| Progreso Lakes, TX | 340 | 42 | 16.0% |
| Donnelsville, OH | 340 | 45 | 10.0% |