| Month | Temp. (min) | Temp. (max) | Temp. (avg) | Precipitation |
| January | 31°F | 54°F | 40°F | 3.5" |
| February | 35°F | 58°F | 45°F | 6.3" |
| March | 45°F | 68°F | 55°F | 7.9" |
| April | 52°F | 76°F | 63°F | 8.9" |
| May | 60°F | 81°F | 70°F | 12.3" |
| June | 69°F | 91°F | 80°F | 6.5" |
| July | 72°F | 94°F | 83°F | 11.1" |
| August | 72°F | 94°F | 82°F | 5.8" |
| September | 63°F | 87°F | 74°F | 10.6" |
| October | 51°F | 77°F | 63°F | 8.8" |
| November | 42°F | 66°F | 53°F | 12.5" |
| December | 34°F | 55°F | 43°F | 13.6" |
| Index | Heavener | Oklahoma | National |
| Air quality index | 36 | 55 | 42 |
| Pollution index | 1,131,940 | 1,271,533 | 2,726,193 |
| Measurement | Total |
| Days measured | 361 |
| Days with good air quality | 323 |
| Days with moderate air quality | 38 |
| Days w/ poor A.Q. for sensitive groups | 0 |
| Days with unhealthy air quality | 0 |
| Pollutant | Total |
| Arsenic | 0.003% |
| Benzene | 0.020% |
| Carbon Tetrachloride | 0.002% |
| Lead | 0.010% |
| Mercury | 0.190% |
| City | Population | Air Quality Index | National Avg. |
| Hartford, AR | 758 | 36 | 28.0% |
| Monroe, OK | 169 | 36 | 28.0% |
| Midland, AR | 341 | 36 | 28.0% |
| Poteau, OK | 8,866 | 36 | 28.0% |
| Whitesboro, OK | 232 | 36 | 28.0% |
| Heavener, OK | 3,298 | 36 | 28.0% |
| City | Population | Air Quality Index | National Avg. |
| Hauula, HI | 3,298 | 30 | 40.0% |
| Cherryvale, SC | 3,298 | 43 | 14.0% |
| West Point, VA | 3,297 | 44 | 12.0% |
| East Hawkesbury, ON | 3,297 | n/a | |
| Elma, WA | 3,299 | 20 | 60.0% |
| Heavener, OK | 3,298 | 36 | 28.0% |
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