| Month | Temp. (min) | Temp. (max) | Temp. (avg) | Precipitation |
| January | 29°F | 55°F | 41°F | 3.1" |
| February | 32°F | 59°F | 44°F | 2.4" |
| March | 41°F | 69°F | 54°F | 4.4" |
| April | 50°F | 78°F | 63°F | 5.5" |
| May | 58°F | 83°F | 70°F | 7.2" |
| June | 69°F | 92°F | 80°F | 4.0" |
| July | 72°F | 96°F | 83°F | 4.0" |
| August | 71°F | 95°F | 82°F | 4.2" |
| September | 63°F | 89°F | 75°F | 4.8" |
| October | 51°F | 79°F | 63°F | 5.2" |
| November | 40°F | 68°F | 53°F | 3.3" |
| December | 31°F | 56°F | 42°F | 3.5" |
| Index | Rock Island | 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% |
| Barling, AR | 4,957 | 36 | 28.0% |
| Greenwood, AR | 9,392 | 36 | 28.0% |
| Fort Coffee, OK | 475 | 36 | 28.0% |
| Panama, OK | 1,401 | 36 | 28.0% |
| Rock Island, OK | 827 | 36 | 28.0% |
| City | Population | Air Quality Index | National Avg. |
| Rockford, IA | 827 | 15 | 70.0% |
| Ashton, IL | 827 | 42 | 16.0% |
| Oxford, MD | 827 | 41 | 18.0% |
| Mayville, MI | 827 | 38 | 24.0% |
| White Oak, MS | 827 | 45 | 10.0% |
| Rock Island, OK | 827 | 36 | 28.0% |
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