Santiago do Cacem, Portugal offers 3 beaches perfect for sunbathing, surfing, swimming, and more. Longboat Key is known for its luxurious resorts, pristine beaches, and the Longboat Key Club. The best time to travel to Santiago do Cacem, Portugal, is from May to September, with average air temperatures ranging from 20°C to 30°C and water temperatures around 18°C to 22°C. Sandee provides detailed maps, photos, and reviews from fellow beachgoers to help you Choose Your Beach™ and plan your perfect beach vacation!