| Month | Temp. (min) | Temp. (max) | Temp. (avg) | Precipitation |
| January | 22°F | 40°F | 30°F | 3.3" |
| February | 23°F | 42°F | 32°F | 2.7" |
| March | 35°F | 57°F | 45°F | 4.6" |
| April | 44°F | 69°F | 56°F | 6.0" |
| May | 53°F | 76°F | 64°F | 5.0" |
| June | 62°F | 84°F | 73°F | 6.1" |
| July | 64°F | 86°F | 75°F | 4.9" |
| August | 62°F | 86°F | 73°F | 3.0" |
| September | 55°F | 80°F | 66°F | 3.6" |
| October | 44°F | 68°F | 55°F | 4.1" |
| November | 33°F | 56°F | 44°F | 3.5" |
| December | 26°F | 44°F | 35°F | 4.4" |
| Index | Seymour | Indiana | National |
| Air quality index | 35 | 56 | 42 |
| Pollution index | 751,900 | 2,719,453 | 2,726,193 |
| Measurement | Total |
| Days measured | 360 |
| Days with good air quality | 340 |
| Days with moderate air quality | 20 |
| Days w/ poor A.Q. for sensitive groups | 0 |
| Days with unhealthy air quality | 0 |
| Pollutant | Total |
| Arsenic | 0.001% |
| Benzene | 0.010% |
| Carbon Tetrachloride | 0.002% |
| Lead | 0.000% |
| Mercury | 0.000% |
| City | Population | Air Quality Index | National Avg. |
| Deputy, IN | 35 | 35 | 30.0% |
| Jonesville, IN | 230 | 35 | 30.0% |
| Austin, IN | 3,973 | 35 | 30.0% |
| North Vernon, IN | 7,415 | 35 | 30.0% |
| Brownstown, IN | 3,021 | 35 | 30.0% |
| Seymour, IN | 20,201 | 35 | 30.0% |
| City | Population | Air Quality Index | National Avg. |
| North Bay Shore, NY | 20,198 | 43 | 14.0% |
| Stillwater, MN | 20,207 | 46 | 8.0% |
| Rivière-du-Loup, QC | 20,207 | n/a | |
| West Mifflin, PA | 20,208 | 56 | 12.0% |
| West Hempstead, NY | 20,191 | 51 | 2.0% |
| Seymour, IN | 20,201 | 35 | 30.0% |