| Month | Temp. (min) | Temp. (max) | Temp. (avg) | Precipitation |
| January | 27°F | 45°F | 35°F | 4.8" |
| February | 28°F | 47°F | 36°F | 6.4" |
| March | 36°F | 57°F | 46°F | 6.0" |
| April | 45°F | 68°F | 56°F | 6.7" |
| May | 55°F | 76°F | 65°F | 6.5" |
| June | 64°F | 84°F | 74°F | 8.6" |
| July | 68°F | 88°F | 78°F | 8.7" |
| August | 66°F | 86°F | 76°F | 7.5" |
| September | 60°F | 80°F | 69°F | 8.6" |
| October | 49°F | 69°F | 58°F | 8.1" |
| November | 38°F | 58°F | 47°F | 7.5" |
| December | 32°F | 50°F | 40°F | 7.1" |
| Index | District Heights | Maryland | National |
| Air quality index | 47 | 43 | 42 |
| Pollution index | 849,185 | 5,342,367 | 2,726,193 |
| Measurement | Total |
| Days measured | 365 |
| Days with good air quality | 209 |
| Days with moderate air quality | 145 |
| Days w/ poor A.Q. for sensitive groups | 10 |
| Days with unhealthy air quality | 1 |
| Pollutant | Total |
| Arsenic | 0.010% |
| Benzene | 0.020% |
| Carbon Tetrachloride | 0.002% |
| Lead | 0.003% |
| Mercury | 0.000% |
| City | Population | Air Quality Index | National Avg. |
| Odenton, MD | 43,210 | 46 | 8.0% |
| Forest Glen, MD | 6,097 | 47 | 6.0% |
| North Chevy Chase, MD | 575 | 47 | 6.0% |
| Mount Vernon, VA | 13,952 | 47 | 6.0% |
| Washington, DC | 721,713 | 47 | 6.0% |
| District Heights, MD | 6,150 | 47 | 6.0% |
| City | Population | Air Quality Index | National Avg. |
| Snyderville, UT | 6,150 | 51 | 2.0% |
| Gardnerville, NV | 6,149 | 13 | 74.0% |
| Highland Lakes, AL | 6,151 | 53 | 6.0% |
| Charles Town, WV | 6,151 | 38 | 24.0% |
| Fort Washington, PA | 6,152 | 51 | 2.0% |
| District Heights, MD | 6,150 | 47 | 6.0% |