| | Arnold, MD | Carrollton, VA | United States |
| Rainfall | 43.7 | 45.6 | 38.1 |
| Snowfall | 13.5 | 4.6 | 27.8 |
| Precipitation Days | 115.9 | 113.5 | 106.2 |
| Sunny | 210 | 213 | 205 |
| Avg. July High | 87.2 | 88.9 | 85.8 |
| Avg. Jan. Low | 28.4 | 33.5 | 21.7 |
| Comfort Index (higher=better) | 7.3 | 7.5 | 7 |
| UV Index | 4 | 4.4 | 4.3 |
| Elevation ft. | 135 | 23 | 2443 |