| Potomac Mills, VA | Herndon, VA | United States |
Rainfall | 42 | 43 | 38 |
Snowfall | 18 | 22 | 28 |
Precipitation | 118 | 120 | 106 |
Sunny | 198 | 201 | 205 |
Avg. July High | 87 | 86 | 86 |
Avg. Jan. Low | 24 | 24 | 22 |
Comfort Index (higher=better) | 7.3 | 7.3 | 7 |
UV Index | 4 | 4 | 4.3 |
Elevation | 203 | 361 | 2443 |