| Month | Temp. (min) | Temp. (max) | Temp. (avg) | Precipitation |
| January | 20°F | 52°F | 34°F | 0.4" |
| February | 23°F | 54°F | 37°F | 0.6" |
| March | 31°F | 64°F | 46°F | 1.2" |
| April | 39°F | 73°F | 54°F | 0.7" |
| May | 49°F | 81°F | 64°F | 1.2" |
| June | 59°F | 91°F | 75°F | 2.6" |
| July | 63°F | 92°F | 77°F | 3.5" |
| August | 62°F | 90°F | 75°F | 3.1" |
| September | 53°F | 83°F | 67°F | 1.5" |
| October | 41°F | 73°F | 55°F | 2.3" |
| November | 29°F | 64°F | 45°F | 0.1" |
| December | 20°F | 50°F | 33°F | 0.6" |
| Index | Dalhart | Texas | National |
| Air quality index | 44 | 52 | 42 |
| Pollution index | 628,595 | 2,009,300 | 2,726,193 |
| Measurement | Total |
| Days measured | 365 |
| Days with good air quality | 259 |
| Days with moderate air quality | 96 |
| Days w/ poor A.Q. for sensitive groups | 10 |
| Days with unhealthy air quality | 0 |
| Pollutant | Total |
| Arsenic | 0.000% |
| Benzene | 0.005% |
| Carbon Tetrachloride | 0.000% |
| Lead | 0.010% |
| Mercury | 0.000% |
| City | Population | Air Quality Index | National Avg. |
| Hartley, TX | 513 | 44 | 12.0% |
| Dalhart, TX | 8,740 | 44 | 12.0% |
| City | Population | Air Quality Index | National Avg. |
| Tuscumbia, AL | 8,741 | 37 | 26.0% |
| Perryville, MO | 8,741 | 54 | 8.0% |
| Malverne, NY | 8,738 | 51 | 2.0% |
| Fallon, NV | 8,742 | 41 | 18.0% |
| Park Hills, MO | 8,743 | 54 | 8.0% |
| Dalhart, TX | 8,740 | 44 | 12.0% |