| Month | Temp. (min) | Temp. (max) | Temp. (avg) | Precipitation |
| January | 35°F | 56°F | 44°F | 3.9" |
| February | 38°F | 59°F | 47°F | 3.1" |
| March | 46°F | 68°F | 56°F | 6.0" |
| April | 55°F | 77°F | 65°F | 5.1" |
| May | 61°F | 83°F | 72°F | 3.1" |
| June | 70°F | 91°F | 80°F | 2.9" |
| July | 72°F | 93°F | 82°F | 3.1" |
| August | 72°F | 93°F | 81°F | 3.4" |
| September | 65°F | 90°F | 76°F | 2.7" |
| October | 53°F | 79°F | 65°F | 3.6" |
| November | 44°F | 67°F | 54°F | 4.1" |
| December | 39°F | 57°F | 47°F | 4.2" |
| Index | Greenville | Mississippi | National |
| Air quality index | 43 | 40 | 42 |
| Pollution index | 2,498,240 | 1,514,109 | 2,726,193 |
| Measurement | Total |
| Days measured | 364 |
| Days with good air quality | 270 |
| Days with moderate air quality | 94 |
| Days w/ poor A.Q. for sensitive groups | 0 |
| Days with unhealthy air quality | 0 |
| Pollutant | Total |
| Arsenic | 0.001% |
| Benzene | 0.060% |
| Carbon Tetrachloride | 0.002% |
| Lead | 0.020% |
| Mercury | 0.004% |
| City | Population | Air Quality Index | National Avg. |
| Hollandale, MS | 2,053 | 43 | 14.0% |
| Leland, MS | 4,020 | 43 | 14.0% |
| Lake Village, AR | 2,345 | 43 | 14.0% |
| Metcalfe, MS | 973 | 43 | 14.0% |
| Arcola, MS | 305 | 43 | 14.0% |
| Greenville, MS | 30,605 | 43 | 14.0% |
| City | Population | Air Quality Index | National Avg. |
| Texarkana, AR | 30,581 | 39 | 22.0% |
| Middle River, MD | 30,630 | 46 | 8.0% |
| Highland Park, IL | 30,564 | 55 | 10.0% |
| Suisun City, CA | 30,544 | 35 | 30.0% |
| Walnut, CA | 30,544 | 89 | 78.0% |
| Greenville, MS | 30,605 | 43 | 14.0% |