San Isidro, Culebra, Puerto Rico, United States offers 1 beach perfect for sunbathing, surfing, swimming, and more. Culebra, Puerto Rico is known for Flamenco Beach, one of the most beautiful beaches in the world. The best time to travel to San Isidro, Culebra, Puerto Rico, is from December to April, with average air temperatures around 80°F (27°C) and water temperatures near 79°F (26°C). Sandee provides detailed maps, photos, and reviews from fellow beachgoers to help you Choose Your Beach™ and plan your perfect beach vacation!