| Month | Temp. (min) | Temp. (max) | Temp. (avg) | Precipitation |
| January | 32°F | 56°F | 43°F | 4.8" |
| February | 34°F | 59°F | 45°F | 3.8" |
| March | 42°F | 69°F | 55°F | 5.0" |
| April | 50°F | 78°F | 63°F | 5.3" |
| May | 58°F | 84°F | 71°F | 4.9" |
| June | 68°F | 91°F | 79°F | 4.0" |
| July | 71°F | 93°F | 81°F | 5.1" |
| August | 71°F | 93°F | 81°F | 4.1" |
| September | 63°F | 88°F | 74°F | 4.5" |
| October | 50°F | 78°F | 63°F | 4.5" |
| November | 40°F | 67°F | 52°F | 4.1" |
| December | 35°F | 58°F | 46°F | 6.1" |
| Index | Marietta | Mississippi | National |
| Air quality index | 39 | 40 | 42 |
| Pollution index | 929,930 | 1,514,109 | 2,726,193 |
| Measurement | Total |
| Days measured | 241 |
| Days with good air quality | 222 |
| Days with moderate air quality | 19 |
| Days w/ poor A.Q. for sensitive groups | 0 |
| Days with unhealthy air quality | 0 |
| Pollutant | Total |
| Arsenic | 0.000% |
| Benzene | 0.010% |
| Carbon Tetrachloride | 0.002% |
| Lead | 0.004% |
| Mercury | 0.000% |
| City | Population | Air Quality Index | National Avg. |
| Paden, MS | 107 | 37 | 26.0% |
| Tishomingo, MS | 466 | 37 | 26.0% |
| Booneville, MS | 8,539 | 39 | 22.0% |
| Baldwyn, MS | 3,093 | 39 | 22.0% |
| Mantachie, MS | 1,726 | 39 | 22.0% |
| Marietta, MS | 208 | 39 | 22.0% |
| City | Population | Air Quality Index | National Avg. |
| Watson, AR | 208 | 43 | 14.0% |
| Garden City, CO | 208 | 45 | 10.0% |
| Campbellton, FL | 208 | 35 | 30.0% |
| Chesterfield, IL | 208 | 40 | 20.0% |
| Hardtner, KS | 208 | 40 | 20.0% |
| Marietta, MS | 208 | 39 | 22.0% |
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