| Month | Temp. (min) | Temp. (max) | Temp. (avg) | Precipitation |
| January | 41°F | 59°F | 48°F | 8.4" |
| February | 43°F | 62°F | 52°F | 4.5" |
| March | 51°F | 71°F | 60°F | 10.6" |
| April | 54°F | 75°F | 64°F | 2.9" |
| May | 64°F | 83°F | 72°F | 10.4" |
| June | 72°F | 90°F | 80°F | 8.5" |
| July | 73°F | 91°F | 81°F | 6.3" |
| August | 74°F | 95°F | 84°F | 4.5" |
| September | 71°F | 92°F | 80°F | 10.6" |
| October | 58°F | 82°F | 69°F | 7.6" |
| November | 50°F | 73°F | 60°F | 4.0" |
| December | 39°F | 63°F | 50°F | 3.7" |
| Index | Gun Barrel City | Texas | National |
| Air quality index | 41 | 52 | 42 |
| Pollution index | 37,723,200 | 2,009,300 | 2,726,193 |
| Measurement | Total |
| Days measured | 365 |
| Days with good air quality | 275 |
| Days with moderate air quality | 80 |
| Days w/ poor A.Q. for sensitive groups | 7 |
| Days with unhealthy air quality | 3 |
| Pollutant | Total |
| Arsenic | 0.060% |
| Benzene | 0.290% |
| Carbon Tetrachloride | 0.220% |
| Lead | 0.230% |
| Mercury | 0.020% |
| City | Population | Air Quality Index | National Avg. |
| Kerens, TX | 1,864 | 41 | 18.0% |
| Trinidad, TX | 868 | 41 | 18.0% |
| Payne Springs, TX | 725 | 41 | 18.0% |
| Log Cabin, TX | 900 | 41 | 18.0% |
| Grays Prairie, TX | 290 | 41 | 18.0% |
| Gun Barrel City, TX | 6,401 | 41 | 18.0% |
| City | Population | Air Quality Index | National Avg. |
| Blakely, PA | 6,400 | 38 | 24.0% |
| Wailea, HI | 6,405 | 15 | 70.0% |
| Wainwright, AB | 6,405 | n/a | |
| Antigonish, Subd. B, NS | 6,396 | n/a | |
| Highgrove, CA | 6,406 | 89 | 78.0% |
| Gun Barrel City, TX | 6,401 | 41 | 18.0% |