| Month | Temp. (min) | Temp. (max) | Temp. (avg) | Precipitation |
| January | 19°F | 35°F | 27°F | 2.0" |
| February | 19°F | 36°F | 27°F | 1.9" |
| March | 30°F | 50°F | 39°F | 2.7" |
| April | 39°F | 63°F | 51°F | 3.8" |
| May | 50°F | 74°F | 62°F | 3.9" |
| June | 59°F | 83°F | 71°F | 4.0" |
| July | 62°F | 85°F | 74°F | 3.3" |
| August | 60°F | 84°F | 72°F | 3.6" |
| September | 54°F | 78°F | 65°F | 3.2" |
| October | 44°F | 65°F | 53°F | 2.6" |
| November | 33°F | 52°F | 42°F | 2.8" |
| December | 25°F | 39°F | 32°F | 2.4" |
| Index | Butler | Indiana | National |
| Air quality index | 45 | 56 | 42 |
| Pollution index | 3,274,520 | 2,719,453 | 2,726,193 |
| Measurement | Total |
| Days measured | 365 |
| Days with good air quality | 236 |
| Days with moderate air quality | 128 |
| Days w/ poor A.Q. for sensitive groups | 1 |
| Days with unhealthy air quality | 0 |
| Pollutant | Total |
| Arsenic | 0.002% |
| Benzene | 0.020% |
| Carbon Tetrachloride | 0.002% |
| Lead | 0.010% |
| Mercury | 0.003% |
| City | Population | Air Quality Index | National Avg. |
| Montpelier, OH | 4,093 | 39 | 22.0% |
| Ashley, IN | 1,082 | 45 | 10.0% |
| Hudson, IN | 523 | 45 | 10.0% |
| St. Joe, IN | 466 | 45 | 10.0% |
| Edon, OH | 904 | 45 | 10.0% |
| Butler, IN | 2,958 | 45 | 10.0% |
| City | Population | Air Quality Index | National Avg. |
| Lanai City, HI | 2,958 | 15 | 70.0% |
| Natalbany, LA | 2,958 | 30 | 40.0% |
| Bishop's Falls, NL | 2,958 | n/a | |
| Bunnell, FL | 2,957 | 31 | 38.0% |
| Claryville, KY | 2,957 | 54 | 8.0% |
| Butler, IN | 2,958 | 45 | 10.0% |