| Month | Temp. (min) | Temp. (max) | Temp. (avg) | Precipitation |
| January | 30°F | 56°F | 42°F | 8.3" |
| February | 34°F | 60°F | 45°F | 7.1" |
| March | 43°F | 68°F | 55°F | 10.8" |
| April | 51°F | 78°F | 64°F | 6.1" |
| May | 58°F | 83°F | 70°F | 9.0" |
| June | 69°F | 91°F | 79°F | 7.6" |
| July | 70°F | 93°F | 81°F | 8.8" |
| August | 69°F | 93°F | 80°F | 7.7" |
| September | 62°F | 91°F | 75°F | 10.0" |
| October | 52°F | 80°F | 65°F | 11.1" |
| November | 39°F | 65°F | 51°F | 8.8" |
| December | 36°F | 58°F | 46°F | 9.9" |
| Index | Thornton | Arkansas | National |
| Air quality index | 4 | 38 | 50 |
| Pollution index | 457,668 | 1,270,108 | 5,066,862 |
| Measurement | Total |
| Days measured | 362 |
| Days with good air quality | 328 |
| Days with moderate air quality | 34 |
| Days w/ poor A.Q. for sensitive groups | |
| Days with unhealthy air quality |
| Pollutant | Total |
| Arsenic | 0.000% |
| Benzene | 0.010% |
| Carbon Tetrachloride | 0.000% |
| Lead | 0.030% |
| Mercury | 0.000% |
| City, State | Population | Air Quality Index | National Avg. |
| Bearden, AR | 953 | 4 | 92% |
| New Edinburg, AR | 469 | 4 | 92% |
| East Camden, AR | 979 | 4 | 92% |
| Tinsman, AR | 44 | 4 | 92% |
| Banks, AR | 119 | 4 | 92% |
| Thornton, AR | 641 | 4 | 92% |
| City, State | Population | Air Quality Index | National Avg. |
| Eldred, PA | 641 | 33 | 34% |
| Flintville, TN | 641 | 37 | 26% |
| Glen Fork, WV | 641 | 295 | 490% |
| Meadow, TX | 641 | 26 | 48% |
| Williston, OH | 641 | 36 | 28% |
| Thornton, AR | 641 | 4 | 92% |