| Month | Temp. (min) | Temp. (max) | Temp. (avg) | Precipitation |
| January | 26°F | 45°F | 35°F | 4.6" |
| February | 27°F | 48°F | 37°F | 4.1" |
| March | 36°F | 59°F | 47°F | 5.4" |
| April | 45°F | 70°F | 57°F | 6.6" |
| May | 54°F | 77°F | 66°F | 7.2" |
| June | 63°F | 86°F | 74°F | 10.2" |
| July | 67°F | 89°F | 78°F | 8.7" |
| August | 66°F | 87°F | 76°F | 7.4" |
| September | 59°F | 81°F | 69°F | 11.4" |
| October | 48°F | 70°F | 58°F | 8.8" |
| November | 37°F | 59°F | 47°F | 5.7" |
| December | 31°F | 50°F | 40°F | 5.9" |
| Index | Merrifield | Virginia | National |
| Air quality index | 47 | 58 | 42 |
| Pollution index | 208,434 | 1,561,881 | 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 | 0.003% |
| Benzene | 0.002% |
| Carbon Tetrachloride | 0.001% |
| Lead | 0.001% |
| Mercury | 0.000% |
| City | Population | Air Quality Index | National Avg. |
| Falls Church, VA | 14,309 | 47 | 6.0% |
| Hybla Valley, VA | 18,438 | 47 | 6.0% |
| Lincolnia, VA | 22,579 | 47 | 6.0% |
| Ravensworth, VA | 2,841 | 47 | 6.0% |
| Springfield, VA | 32,960 | 47 | 6.0% |
| Merrifield, VA | 18,523 | 47 | 6.0% |
| City | Population | Air Quality Index | National Avg. |
| Lake Shore, MD | 18,523 | 46 | 8.0% |
| Concord, MO | 18,521 | 54 | 8.0% |
| Brookfield, IL | 18,520 | 55 | 10.0% |
| Winchester, KY | 18,520 | 42 | 16.0% |
| Milledgeville, GA | 18,526 | 38 | 24.0% |
| Merrifield, VA | 18,523 | 47 | 6.0% |
Here are the best places to live in Virginia
Check out the 10 safest cities in Virginia
These are the 10 cheapest cities in Virginia
Most Dangerous States In The US