| Month | Temp. (min) | Temp. (max) | Temp. (avg) | Precipitation |
| January | 31°F | 64°F | 45°F | 0.4" |
| February | 34°F | 71°F | 50°F | 0.1" |
| March | 41°F | 80°F | 59°F | 0.5" |
| April | 49°F | 88°F | 68°F | 0.6" |
| May | 58°F | 93°F | 75°F | 1.6" |
| June | 68°F | 101°F | 84°F | 0.6" |
| July | 71°F | 99°F | 84°F | 1.5" |
| August | 70°F | 98°F | 83°F | 1.8" |
| September | 63°F | 91°F | 76°F | 1.5" |
| October | 51°F | 85°F | 67°F | 0.7" |
| November | 38°F | 73°F | 54°F | 0.6" |
| December | 32°F | 64°F | 46°F | 0.6" |
| Index | Pecos | Texas | National |
| Air quality index | 28 | 52 | 42 |
| Pollution index | 510,722 | 2,009,300 | 2,726,193 |
| Measurement | Total |
| Days measured | 354 |
| Days with good air quality | 319 |
| Days with moderate air quality | 35 |
| Days w/ poor A.Q. for sensitive groups | 0 |
| Days with unhealthy air quality | 0 |
| Pollutant | Total |
| Arsenic | 0.000% |
| Benzene | 0.020% |
| Carbon Tetrachloride | 0.000% |
| Lead | 0.000% |
| Mercury | 0.000% |
| City | Population | Air Quality Index | National Avg. |
| Barstow, TX | 377 | 28 | 44.0% |
| Pecos, TX | 12,252 | 28 | 44.0% |
| City | Population | Air Quality Index | National Avg. |
| Claiborne, LA | 12,252 | 34 | 32.0% |
| Delhi, CA | 12,257 | 48 | 4.0% |
| Sedro-Woolley, WA | 12,262 | 24 | 52.0% |
| Union, MO | 12,241 | 54 | 8.0% |
| South Miami, FL | 12,237 | 41 | 18.0% |
| Pecos, TX | 12,252 | 28 | 44.0% |