| Ukiah to Smolyan | 6,505.52 mi (10,469.62 km) |
| Ukiah to Sofia | 6,406.00 mi (10,309.47 km) |
| Ukiah to Sopot | 6,439.44 mi (10,363.28 km) |
| Ukiah to Sozopol | 6,513.60 mi (10,482.62 km) |
| Ukiah to Sredets | 6,508.14 mi (10,473.83 km) |
| Ukiah to Stamboliyski | 6,467.38 mi (10,408.24 km) |
| Ukiah to Stara Zagora | 6,471.76 mi (10,415.30 km) |
| Ukiah to Svilengrad | 6,525.24 mi (10,501.37 km) |
| Ukiah to Svishtov | 6,390.83 mi (10,285.05 km) |
| Ukiah to Targovishte | 6,438.70 mi (10,362.08 km) |
| Ukiah to Teteven | 6,412.51 mi (10,319.93 km) |
| Ukiah to Troyan | 6,424.06 mi (10,338.52 km) |
| Ukiah to Tryavna | 6,441.27 mi (10,366.22 km) |
| Ukiah to Tutrakan | 6,388.46 mi (10,281.24 km) |
| Ukiah to Varna | 6,466.53 mi (10,406.88 km) |
