| Month | Temp. (min) | Temp. (max) | Temp. (avg) | Precipitation |
| January | 43°F | 61°F | 51°F | 8.4" |
| February | 47°F | 65°F | 55°F | 5.0" |
| March | 54°F | 74°F | 63°F | 7.9" |
| April | 57°F | 78°F | 66°F | 5.5" |
| May | 66°F | 86°F | 75°F | 8.9" |
| June | 74°F | 93°F | 83°F | 4.7" |
| July | 74°F | 93°F | 82°F | 8.0" |
| August | 75°F | 95°F | 84°F | 10.3" |
| September | 71°F | 92°F | 80°F | 5.8" |
| October | 58°F | 82°F | 69°F | 4.4" |
| November | 52°F | 74°F | 62°F | 9.7" |
| December | 43°F | 65°F | 53°F | 3.3" |
| Index | Huntsville | Texas | National |
| Air quality index | 52 | 52 | 42 |
| Pollution index | 483,161 | 2,009,300 | 2,726,193 |
| Measurement | Total |
| Days measured | 365 |
| Days with good air quality | 171 |
| Days with moderate air quality | 163 |
| Days w/ poor A.Q. for sensitive groups | 26 |
| Days with unhealthy air quality | 4 |
| Pollutant | Total |
| Arsenic | 0.001% |
| Benzene | 0.010% |
| Carbon Tetrachloride | 0.001% |
| Lead | 0.000% |
| Mercury | 0.000% |
| City | Population | Air Quality Index | National Avg. |
| Riverside, TX | 471 | 52 | 4.0% |
| New Waverly, TX | 940 | 52 | 4.0% |
| Oakhurst, TX | 178 | 52 | 4.0% |
| Huntsville, TX | 43,308 | 52 | 4.0% |
| City | Population | Air Quality Index | National Avg. |
| West Babylon, NY | 43,319 | 51 | 2.0% |
| Oakley, CA | 43,283 | 45 | 10.0% |
| Apache Junction, AZ | 43,334 | 74 | 48.0% |
| Rouyn-Noranda, QC | 43,276 | n/a | |
| Beverly, MA | 43,236 | 43 | 14.0% |
| Huntsville, TX | 43,308 | 52 | 4.0% |