| Month | Temp. (min) | Temp. (max) | Temp. (avg) | Precipitation |
| January | 45°F | 69°F | 55°F | 5.0" |
| February | 49°F | 73°F | 59°F | 4.6" |
| March | 55°F | 78°F | 65°F | 4.8" |
| April | 62°F | 84°F | 72°F | 4.4" |
| May | 68°F | 89°F | 77°F | 6.5" |
| June | 73°F | 95°F | 83°F | 6.0" |
| July | 74°F | 95°F | 83°F | 8.1" |
| August | 74°F | 97°F | 84°F | 8.9" |
| September | 70°F | 92°F | 79°F | 6.1" |
| October | 62°F | 87°F | 73°F | 3.5" |
| November | 55°F | 77°F | 65°F | 4.7" |
| December | 48°F | 69°F | 57°F | 2.8" |
| Index | Three Rivers | Texas | National |
| Air quality index | 30 | 52 | 42 |
| Pollution index | 298,412 | 2,009,300 | 2,726,193 |
| Measurement | Total |
| Days measured | 284 |
| Days with good air quality | 234 |
| Days with moderate air quality | 50 |
| Days w/ poor A.Q. for sensitive groups | 0 |
| Days with unhealthy air quality | 0 |
| Pollutant | Total |
| Arsenic | 0.000% |
| Benzene | 0.004% |
| Carbon Tetrachloride | 0.000% |
| Lead | 0.000% |
| Mercury | 0.000% |
| City | Population | Air Quality Index | National Avg. |
| George West, TX | 2,646 | 30 | 40.0% |
| Pawnee, TX | 89 | 31 | 38.0% |
| Three Rivers, TX | 2,109 | 30 | 40.0% |
| City | Population | Air Quality Index | National Avg. |
| Milton, LA | 2,109 | 41 | 18.0% |
| Newaygo, MI | 2,109 | 38 | 24.0% |
| Parkside, PA | 2,109 | 51 | 2.0% |
| Okanagan-Similkameen A, BC | 2,109 | n/a | |
| Linden, CA | 2,108 | 45 | 10.0% |
| Three Rivers, TX | 2,109 | 30 | 40.0% |