| Month | Temp. (min) | Temp. (max) | Temp. (avg) | Precipitation |
| January | 44°F | 64°F | 53°F | 5.6" |
| February | 47°F | 67°F | 56°F | 4.5" |
| March | 54°F | 74°F | 63°F | 3.3" |
| April | 60°F | 81°F | 70°F | 4.9" |
| May | 67°F | 86°F | 76°F | 5.8" |
| June | 73°F | 91°F | 81°F | 5.8" |
| July | 75°F | 92°F | 82°F | 5.9" |
| August | 75°F | 93°F | 82°F | 7.6" |
| September | 71°F | 89°F | 79°F | 5.5" |
| October | 60°F | 82°F | 70°F | 3.6" |
| November | 51°F | 73°F | 61°F | 4.1" |
| December | 46°F | 66°F | 55°F | 5.9" |
| Index | Henderson | Louisiana | National |
| Air quality index | 41 | 106 | 42 |
| Pollution index | 394,287 | 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 | 0.000% |
| Benzene | 0.010% |
| Carbon Tetrachloride | 0.001% |
| Lead | 0.000% |
| Mercury | 0.000% |
| City | Population | Air Quality Index | National Avg. |
| Broussard, LA | 12,710 | 41 | 18.0% |
| Grand Coteau, LA | 1,071 | 41 | 18.0% |
| Parks, LA | 906 | 41 | 18.0% |
| Carencro, LA | 9,636 | 41 | 18.0% |
| Lafayette, LA | 131,168 | 41 | 18.0% |
| Henderson, LA | 2,313 | 41 | 18.0% |
| City | Population | Air Quality Index | National Avg. |
| Campbell, FL | 2,313 | 39 | 22.0% |
| Altamont, IL | 2,313 | 40 | 20.0% |
| Owens Cross Roads, AL | 2,312 | 44 | 12.0% |
| Rushville, IL | 2,312 | 41 | 18.0% |
| Perry, MI | 2,312 | 36 | 28.0% |
| Henderson, LA | 2,313 | 41 | 18.0% |