| Month | Temp. (min) | Temp. (max) | Temp. (avg) | Precipitation |
| January | 39°F | 63°F | 49°F | 6.3" |
| February | 43°F | 67°F | 53°F | 6.2" |
| March | 50°F | 74°F | 61°F | 7.4" |
| April | 56°F | 81°F | 68°F | 5.4" |
| May | 61°F | 85°F | 73°F | 5.4" |
| June | 71°F | 91°F | 80°F | 6.1" |
| July | 73°F | 92°F | 81°F | 6.2" |
| August | 72°F | 93°F | 81°F | 5.6" |
| September | 67°F | 89°F | 77°F | 4.5" |
| October | 55°F | 82°F | 67°F | 1.6" |
| November | 45°F | 72°F | 57°F | 2.8" |
| December | 43°F | 65°F | 52°F | 5.5" |
| Index | McLain | Mississippi | National |
| Air quality index | 35 | 40 | 42 |
| Pollution index | 406,994 | 1,514,109 | 2,726,193 |
| Measurement | Total |
| Days measured | 358 |
| Days with good air quality | 298 |
| Days with moderate air quality | 60 |
| 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 | 0.001% |
| Lead | 0.000% |
| Mercury | 0.000% |
| City | Population | Air Quality Index | National Avg. |
| New Augusta, MS | 474 | 35 | 30.0% |
| Beaumont, MS | 963 | 35 | 30.0% |
| Lucedale, MS | 3,209 | 42 | 16.0% |
| McLain, MS | 340 | 35 | 30.0% |
| City | Population | Air Quality Index | National Avg. |
| Bridgeton, NC | 340 | 0 | 100.0% |
| Willard, NM | 340 | 53 | 6.0% |
| Donnelsville, OH | 340 | 45 | 10.0% |
| Camp Sherman, OR | 340 | 20 | 60.0% |
| Progreso Lakes, TX | 340 | 42 | 16.0% |
| McLain, MS | 340 | 35 | 30.0% |