| 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 | Simmesport | Louisiana | National |
| Air quality index | 30 | 106 | 42 |
| Pollution index | 10,683,000 | 2,526,475 | 2,726,193 |
| Measurement | Total |
| Days measured | 119 |
| Days with good air quality | 107 |
| Days with moderate air quality | 12 |
| 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. |
| Mansura, LA | 1,573 | 30 | 40.0% |
| Marksville, LA | 5,575 | 30 | 40.0% |
| Bordelonville, LA | 506 | 30 | 40.0% |
| Moreauville, LA | 1,168 | 30 | 40.0% |
| Cottonport, LA | 1,836 | 30 | 40.0% |
| Simmesport, LA | 1,429 | 30 | 40.0% |
| City | Population | Air Quality Index | National Avg. |
| Marmaduke, AR | 1,429 | 26 | 48.0% |
| Westwood, CA | 1,429 | 46 | 8.0% |
| Ellington, MO | 1,429 | 54 | 8.0% |
| East Spencer, NC | 1,429 | 40 | 20.0% |
| L'Avenir, QC | 1,429 | n/a | |
| Simmesport, LA | 1,429 | 30 | 40.0% |