| | Derwood, MD | Arlington, VA | United States |
| Rainfall | 42.7 | 43.3 | 38.1 |
| Snowfall | 15.8 | 14.9 | 27.8 |
| Precipitation Days | 109.3 | 117 | 106.2 |
| Sunny | 201 | 201 | 205 |
| Avg. July High | 87 | 87.7 | 85.8 |
| Avg. Jan. Low | 25 | 26.5 | 21.7 |
| Comfort Index (higher=better) | 7.3 | 7.3 | 7 |
| UV Index | 4.1 | 4 | 4.3 |
| Elevation ft. | 472 | 236 | 2443 |