| Month | Temp. (min) | Temp. (max) | Temp. (avg) | Precipitation |
| January | 45°F | 66°F | 54°F | 10.3" |
| February | 47°F | 71°F | 59°F | 5.5" |
| March | 56°F | 75°F | 65°F | 10.4" |
| April | 58°F | 79°F | 69°F | 16.1" |
| May | 64°F | 83°F | 73°F | 20.0" |
| June | 71°F | 90°F | 80°F | 11.6" |
| July | 74°F | 93°F | 83°F | 6.7" |
| August | 73°F | 92°F | 81°F | 12.4" |
| September | 68°F | 89°F | 78°F | 8.8" |
| October | 58°F | 83°F | 70°F | 8.6" |
| November | 51°F | 75°F | 62°F | 8.3" |
| December | 48°F | 68°F | 57°F | 12.2" |
| Index | Slidell | Louisiana | National |
| Air quality index | 45 | 106 | 42 |
| Pollution index | 4,700,710 | 2,526,475 | 2,726,193 |
| Measurement | Total |
| Days measured | 365 |
| Days with good air quality | 229 |
| Days with moderate air quality | 134 |
| Days w/ poor A.Q. for sensitive groups | 2 |
| Days with unhealthy air quality | 0 |
| Pollutant | Total |
| Arsenic | 0.003% |
| Benzene | 0.060% |
| Carbon Tetrachloride | 0.010% |
| Lead | 0.030% |
| Mercury | 0.001% |
| City | Population | Air Quality Index | National Avg. |
| Abita Springs, LA | 2,645 | 30 | 40.0% |
| Eden Isle, LA | 8,426 | 45 | 10.0% |
| Nicholson, MS | 2,566 | 45 | 10.0% |
| Lacombe, LA | 7,465 | 45 | 10.0% |
| Pearlington, MS | 833 | 45 | 10.0% |
| Slidell, LA | 28,740 | 45 | 10.0% |
| City | Population | Air Quality Index | National Avg. |
| Zionsville, IN | 28,737 | 54 | 8.0% |
| Williston, ND | 28,744 | 34 | 32.0% |
| Washington, UT | 28,756 | 44 | 12.0% |
| Fridley, MN | 28,718 | 46 | 8.0% |
| Hobart, IN | 28,763 | 37 | 26.0% |
| Slidell, LA | 28,740 | 45 | 10.0% |