| Penafiel to Silver Firs (Washington) | 5,077.22 mi (8,171.00 km) |
| Penafiel to Silver Spring (Maryland) | 3,537.44 mi (5,692.96 km) |
| Penafiel to Silver Springs Shores (Florida) | 4,124.31 mi (6,637.43 km) |
| Penafiel to Silverdale (Washington) | 5,104.45 mi (8,214.83 km) |
| Penafiel to Silverton (Oregon) | 5,237.42 mi (8,428.82 km) |
| Penafiel to Simi Valley (California) | 5,608.22 mi (9,025.56 km) |
| Penafiel to Simpsonville (South Carolina) | 3,931.85 mi (6,327.70 km) |
| Penafiel to Sioux City (Iowa) | 4,311.16 mi (6,938.14 km) |
| Penafiel to Sioux Falls (South Dakota) | 4,287.80 mi (6,900.55 km) |
| Penafiel to Skokie (Illinois) | 3,944.34 mi (6,347.81 km) |
| Penafiel to Sleepy Hollow (New York) | 3,326.02 mi (5,352.71 km) |
| Penafiel to Slidell (Louisiana) | 4,466.25 mi (7,187.73 km) |
| Penafiel to Smithfield (North Carolina) | 3,712.99 mi (5,975.49 km) |
| Penafiel to Smithfield (Utah) | 4,978.42 mi (8,011.99 km) |
| Penafiel to Smithville (Missouri) | 4,345.35 mi (6,993.17 km) |
