| | North Potomac, MD | Upper Marlboro, MD | United States |
| Rainfall | 41.9 | 43.8 | 38.1 |
| Snowfall | 19.1 | 14.7 | 27.8 |
| Precipitation Days | 113.8 | 105.6 | 106.2 |
| Sunny | 201 | 206 | 205 |
| Avg. July High | 84.9 | 87.4 | 85.8 |
| Avg. Jan. Low | 24.6 | 24 | 21.7 |
| Comfort Index (higher=better) | 7.3 | 7.4 | 7 |
| UV Index | 4.1 | 4.3 | 4.3 |
| Elevation ft. | 256 | 26 | 2443 |