Foz do Arelho, Portugal offers 4 beaches perfect for sunbathing, surfing, swimming, and more. Foz do Arelho is known for the Obidos Lagoon and its beautiful beaches. The best time to travel to Foz do Arelho, Portugal, is from June to September, when the average air temperature is around 20-25°C (68-77°F) and the water temperature is approximately 18-20°C (64-68°F). Sandee provides detailed maps, photos, and reviews from fellow beachgoers to help you Choose Your Beach™ and plan your perfect beach vacation!