| Longford to Silver Firs (Washington) | 4,440.38 mi (7,146.11 km) |
| Longford to Silver Spring (Maryland) | 3,309.16 mi (5,325.58 km) |
| Longford to Silver Springs Shores (Florida) | 3,993.72 mi (6,427.27 km) |
| Longford to Silverdale (Washington) | 4,466.08 mi (7,187.47 km) |
| Longford to Silverton (Oregon) | 4,617.60 mi (7,431.31 km) |
| Longford to Simi Valley (California) | 5,098.60 mi (8,205.40 km) |
| Longford to Simpsonville (South Carolina) | 3,722.24 mi (5,990.37 km) |
| Longford to Sioux City (Iowa) | 3,887.52 mi (6,256.36 km) |
| Longford to Sioux Falls (South Dakota) | 3,849.30 mi (6,194.84 km) |
| Longford to Skokie (Illinois) | 3,588.18 mi (5,774.62 km) |
| Longford to Sleepy Hollow (New York) | 3,088.74 mi (4,970.84 km) |
| Longford to Slidell (Louisiana) | 4,246.05 mi (6,833.36 km) |
| Longford to Smithfield (North Carolina) | 3,527.02 mi (5,676.19 km) |
| Longford to Smithfield (Utah) | 4,454.86 mi (7,169.41 km) |
| Longford to Smithville (Missouri) | 3,972.58 mi (6,393.26 km) |
