| Month | Temp. (min) | Temp. (max) | Temp. (avg) | Precipitation |
| January | 40°F | 64°F | 50°F | 3.8" |
| February | 43°F | 67°F | 54°F | 2.7" |
| March | 50°F | 74°F | 61°F | 3.4" |
| April | 57°F | 81°F | 68°F | 3.5" |
| May | 64°F | 86°F | 74°F | 5.7" |
| June | 70°F | 92°F | 80°F | 4.1" |
| July | 72°F | 94°F | 82°F | 4.0" |
| August | 73°F | 95°F | 82°F | 4.3" |
| September | 67°F | 90°F | 77°F | 2.9" |
| October | 57°F | 83°F | 68°F | 4.8" |
| November | 49°F | 73°F | 59°F | 4.3" |
| December | 43°F | 65°F | 52°F | 3.2" |
| Index | Shepherd | Texas | National |
| Air quality index | 52 | 52 | 42 |
| Pollution index | 99,643 | 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 | 0.000% |
| Benzene | 0.001% |
| Carbon Tetrachloride | 0.000% |
| Lead | 0.000% |
| Mercury | 0.000% |
| City | Population | Air Quality Index | National Avg. |
| Goodrich, TX | 320 | 45 | 10.0% |
| Big Thicket Lake Estates, TX | 624 | 45 | 10.0% |
| Coldspring, TX | 1,036 | 52 | 4.0% |
| Cape Royale, TX | 373 | 52 | 4.0% |
| North Cleveland, TX | 294 | 52 | 4.0% |
| Shepherd, TX | 2,574 | 52 | 4.0% |
| City | Population | Air Quality Index | National Avg. |
| Dover-Foxcroft, ME | 2,574 | 31 | 38.0% |
| Privateer, SC | 2,574 | 43 | 14.0% |
| Yardley, PA | 2,573 | 41 | 18.0% |
| Wrangell, AK | 2,575 | 20 | 60.0% |
| Gassville, AR | 2,575 | 36 | 28.0% |
| Shepherd, TX | 2,574 | 52 | 4.0% |