Carvalhal, Portugal offers 2 beaches perfect for sunbathing, surfing, swimming, and more. Carvalhal, Beja, Portugal, is known for its proximity to the Alqueva Dam and Dark Sky Alqueva Reserve. The best time to travel to Carvalhal, Portugal, is from June to September, with average air temperatures around 75°F (24°C) and water temperatures near 68°F (20°C). Sandee provides detailed maps, photos, and reviews from fellow beachgoers to help you Choose Your Beach™ and plan your perfect beach vacation!