| Watford to Ilawa | 844.98 mi (1,359.87 km) |
| Watford to Imielin | 858.53 mi (1,381.67 km) |
| Watford to Inowroclaw | 791.30 mi (1,273.47 km) |
| Watford to Janow Lubelski | 986.04 mi (1,586.87 km) |
| Watford to Jarocin | 762.83 mi (1,227.66 km) |
| Watford to Jaroslaw | 1,008.94 mi (1,623.73 km) |
| Watford to Jasien | 807.11 mi (1,298.91 km) |
| Watford to Jaslo | 962.26 mi (1,548.60 km) |
| Watford to Jastrzebie-Zdroj | 834.65 mi (1,343.24 km) |
| Watford to Jawor | 715.79 mi (1,151.95 km) |
| Watford to Jaworzno | 859.59 mi (1,383.37 km) |
| Watford to Jedrzejow | 896.83 mi (1,443.32 km) |
| Watford to Jelcz-Laskowice | 764.48 mi (1,230.31 km) |
| Watford to Jelenia Gora | 697.64 mi (1,122.74 km) |
| Watford to Jozefoslaw | 911.78 mi (1,467.37 km) |
