| Month | Temp. (min) | Temp. (max) | Temp. (avg) | Precipitation |
| January | 34°F | 56°F | 44°F | 2.5" |
| February | 38°F | 60°F | 47°F | 2.1" |
| March | 47°F | 69°F | 56°F | 2.9" |
| April | 54°F | 76°F | 64°F | 4.7" |
| May | 61°F | 82°F | 71°F | 5.6" |
| June | 71°F | 91°F | 81°F | 4.5" |
| July | 74°F | 95°F | 84°F | 3.1" |
| August | 74°F | 96°F | 84°F | 3.1" |
| September | 67°F | 89°F | 77°F | 2.9" |
| October | 56°F | 79°F | 66°F | 3.1" |
| November | 46°F | 67°F | 56°F | 2.9" |
| December | 37°F | 56°F | 45°F | 2.6" |
| Index | Howe | Texas | National |
| Air quality index | 325 | 52 | 42 |
| Pollution index | 8,884,190 | 2,009,300 | 2,726,193 |
| Measurement | Total |
| Days measured | 138 |
| Days with good air quality | 120 |
| Days with moderate air quality | 17 |
| Days w/ poor A.Q. for sensitive groups | 1 |
| Days with unhealthy air quality |
| Pollutant | Total |
| Arsenic | 0.030% |
| Benzene | 0.070% |
| Carbon Tetrachloride | 0.040% |
| Lead | 0.260% |
| Mercury | 0.020% |
| City | Population | Air Quality Index | National Avg. |
| Celina, TX | 13,935 | 51 | 2.0% |
| Anna, TX | 14,625 | 51 | 2.0% |
| Weston, TX | 241 | 51 | 2.0% |
| Blue Ridge, TX | 861 | 51 | 2.0% |
| Westminster, TX | 786 | 51 | 2.0% |
| Howe, TX | 3,319 | 325 | 550.0% |
| City | Population | Air Quality Index | National Avg. |
| Tyro, NC | 3,319 | 40 | 20.0% |
| Moulton, AL | 3,318 | 41 | 18.0% |
| East Dundee, IL | 3,318 | 55 | 10.0% |
| Newfane, NY | 3,318 | 39 | 22.0% |
| Taylor Creek, OH | 3,320 | 54 | 8.0% |
| Howe, TX | 3,319 | 325 | 550.0% |