| Month | Temp. (min) | Temp. (max) | Temp. (avg) | Precipitation |
| January | 42°F | 65°F | 52°F | 7.3" |
| February | 45°F | 67°F | 54°F | 7.3" |
| March | 52°F | 74°F | 62°F | 7.7" |
| April | 58°F | 80°F | 68°F | 9.7" |
| May | 63°F | 84°F | 73°F | 10.8" |
| June | 71°F | 90°F | 80°F | 6.2" |
| July | 72°F | 90°F | 80°F | 5.8" |
| August | 72°F | 90°F | 80°F | 9.5" |
| September | 69°F | 89°F | 77°F | 8.0" |
| October | 58°F | 82°F | 69°F | 24.8" |
| November | 47°F | 71°F | 57°F | 9.5" |
| December | 46°F | 66°F | 54°F | 10.8" |
| Index | Melville | Louisiana | National |
| Air quality index | 41 | 106 | 42 |
| Pollution index | 10,683,000 | 2,526,475 | 2,726,193 |
| Measurement | Total |
| Days measured | 365 |
| Days with good air quality | 280 |
| Days with moderate air quality | 85 |
| Days w/ poor A.Q. for sensitive groups | 0 |
| Days with unhealthy air quality | 0 |
| Pollutant | Total |
| Arsenic | 0.380% |
| Benzene | 0.010% |
| Carbon Tetrachloride | 0.002% |
| Lead | 0.150% |
| Mercury | 0.250% |
| City | Population | Air Quality Index | National Avg. |
| Krotz Springs, LA | 754 | 41 | 18.0% |
| Palmetto, LA | 156 | 41 | 18.0% |
| Port Barre, LA | 1,666 | 41 | 18.0% |
| Morganza, LA | 645 | 45 | 10.0% |
| Fordoche, LA | 990 | 45 | 10.0% |
| Melville, LA | 931 | 41 | 18.0% |
| City | Population | Air Quality Index | National Avg. |
| Butte Valley, CA | 931 | 46 | 8.0% |
| Heidelberg, MS | 931 | 36 | 28.0% |
| Cedar Hill, NM | 931 | 49 | 2.0% |
| Midvale, OH | 931 | 46 | 8.0% |
| Export, PA | 931 | 56 | 12.0% |
| Melville, LA | 931 | 41 | 18.0% |