| Month | Temp. (min) | Temp. (max) | Temp. (avg) | Precipitation |
| January | 32°F | 65°F | 47°F | 1.0" |
| February | 37°F | 70°F | 52°F | 0.9" |
| March | 45°F | 77°F | 60°F | 2.0" |
| April | 53°F | 85°F | 68°F | 1.9" |
| May | 61°F | 89°F | 74°F | 3.3" |
| June | 69°F | 95°F | 82°F | 2.4" |
| July | 71°F | 96°F | 83°F | 2.1" |
| August | 71°F | 97°F | 83°F | 2.1" |
| September | 64°F | 92°F | 77°F | 2.4" |
| October | 53°F | 84°F | 68°F | 1.9" |
| November | 42°F | 74°F | 57°F | 1.0" |
| December | 34°F | 66°F | 48°F | 0.9" |
| Index | Junction | Texas | National |
| Air quality index | 49 | 52 | 42 |
| Pollution index | 1,112,950 | 2,009,300 | 2,726,193 |
| Measurement | Total |
| Days measured | 365 |
| Days with good air quality | 196 |
| Days with moderate air quality | 163 |
| Days w/ poor A.Q. for sensitive groups | 5 |
| Days with unhealthy air quality | 1 |
| Pollutant | Total |
| Arsenic | 0.002% |
| Benzene | 0.020% |
| Carbon Tetrachloride | 0.002% |
| Lead | 0.005% |
| Mercury | 0.001% |
| City | Population | Air Quality Index | National Avg. |
| Junction, TX | 2,755 | 49 | 2.0% |
| City | Population | Air Quality Index | National Avg. |
| Hudson, CO | 2,755 | 45 | 10.0% |
| Dawson Springs, KY | 2,755 | 40 | 20.0% |
| Polkton, NC | 2,755 | 49 | 2.0% |
| Wellford, SC | 2,755 | 44 | 12.0% |
| Juneau, WI | 2,755 | 40 | 20.0% |
| Junction, TX | 2,755 | 49 | 2.0% |