| Month | Temp. (min) | Temp. (max) | Temp. (avg) | Precipitation |
| January | 37°F | 61°F | 48°F | 10.8" |
| February | 41°F | 64°F | 51°F | 8.1" |
| March | 48°F | 73°F | 59°F | 10.5" |
| April | 55°F | 79°F | 66°F | 9.1" |
| May | 62°F | 85°F | 73°F | 12.5" |
| June | 70°F | 92°F | 80°F | 11.3" |
| July | 73°F | 94°F | 82°F | 8.6" |
| August | 72°F | 96°F | 83°F | 10.3" |
| September | 66°F | 90°F | 77°F | 7.2" |
| October | 55°F | 81°F | 66°F | 9.1" |
| November | 46°F | 70°F | 57°F | 8.2" |
| December | 40°F | 62°F | 50°F | 7.9" |
| Index | Garrison | Texas | National |
| Air quality index | 38 | 52 | 42 |
| Pollution index | 402,347 | 2,009,300 | 2,726,193 |
| Measurement | Total |
| Days measured | 364 |
| Days with good air quality | 296 |
| Days with moderate air quality | 67 |
| Days w/ poor A.Q. for sensitive groups | 1 |
| Days with unhealthy air quality | 0 |
| Pollutant | Total |
| Arsenic | 0.000% |
| Benzene | 0.010% |
| Carbon Tetrachloride | 0.001% |
| Lead | 0.003% |
| Mercury | 0.000% |
| City | Population | Air Quality Index | National Avg. |
| Nacogdoches, TX | 33,996 | 36 | 28.0% |
| Redfield, TX | 57 | 36 | 28.0% |
| Mount Enterprise, TX | 320 | 37 | 26.0% |
| Appleby, TX | 556 | 37 | 26.0% |
| Gary City, TX | 396 | 38 | 24.0% |
| Garrison, TX | 1,371 | 38 | 24.0% |
| City | Population | Air Quality Index | National Avg. |
| Bayard, NE | 1,371 | 19 | 62.0% |
| Sardinia, OH | 1,371 | 43 | 14.0% |
| West Hills, PA | 1,371 | 38 | 24.0% |
| Teulon, MB | 1,371 | n/a | |
| Hudson Bay, SK | 1,371 | n/a | |
| Garrison, TX | 1,371 | 38 | 24.0% |