| Meridian to Mangualde | 5,122.71 mi (8,244.21 km) |
| Meridian to Marco de Canavezes | 5,080.22 mi (8,175.82 km) |
| Meridian to Marinha Grande | 5,119.64 mi (8,239.27 km) |
| Meridian to Massama | 5,154.30 mi (8,295.04 km) |
| Meridian to Matosinhos | 5,059.66 mi (8,142.74 km) |
| Meridian to Mealhada | 5,107.50 mi (8,219.73 km) |
| Meridian to Melgaco | 5,031.04 mi (8,096.68 km) |
| Meridian to Melres | 5,076.49 mi (8,169.82 km) |
| Meridian to Mira | 5,094.40 mi (8,198.64 km) |
| Meridian to Miranda do Corvo | 5,125.57 mi (8,248.81 km) |
| Meridian to Mirandela | 5,101.51 mi (8,210.09 km) |
| Meridian to Mogadouro | 5,126.02 mi (8,249.53 km) |
| Meridian to Moimenta da Beira | 5,110.03 mi (8,223.80 km) |
| Meridian to Moita | 5,170.71 mi (8,321.45 km) |
| Meridian to Moncao | 5,025.24 mi (8,087.34 km) |
