Puerto Viejo, Costa Rica offers 9 beaches perfect for sunbathing, surfing, swimming, and more. Puerto Viejo, Guanacaste, Costa Rica, is known for its proximity to the Rincon de la Vieja National Park. The best time to travel to Puerto Viejo, Costa Rica, is from February to April, with average air temperatures around 80°F (27°C) and water temperatures near 82°F (28°C). Sandee provides detailed maps, photos, and reviews from fellow beachgoers to help you Choose Your Beach™ and plan your perfect beach vacation!