| Gaithersburg to Hormigueros (Puerto Rico) | 1,571.58 mi (2,529.21 km) |
| Gaithersburg to Horn Lake (Mississippi) | 763.79 mi (1,229.20 km) |
| Gaithersburg to Hot Springs (Arkansas) | 931.45 mi (1,499.02 km) |
| Gaithersburg to Hot Springs Village (Arkansas) | 922.21 mi (1,484.15 km) |
| Gaithersburg to Houma (Louisiana) | 1,011.90 mi (1,628.49 km) |
| Gaithersburg to Houston (Texas) | 1,216.83 mi (1,958.30 km) |
| Gaithersburg to Howard (Wisconsin) | 673.31 mi (1,083.59 km) |
| Gaithersburg to Huber Heights (Ohio) | 371.17 mi (597.35 km) |
| Gaithersburg to Hudson (Florida) | 807.80 mi (1,300.03 km) |
| Gaithersburg to Hudson (Ohio) | 266.32 mi (428.61 km) |
| Gaithersburg to Hudson (Wisconsin) | 890.22 mi (1,432.68 km) |
| Gaithersburg to Hueytown (Alabama) | 673.26 mi (1,083.51 km) |
| Gaithersburg to Hugo (Minnesota) | 905.73 mi (1,457.63 km) |
| Gaithersburg to Humacao (Puerto Rico) | 1,602.65 mi (2,579.22 km) |
| Gaithersburg to Humble (Texas) | 1,202.41 mi (1,935.10 km) |
