Guanica, United States offers 10 beaches perfect for sunbathing, surfing, swimming, and more. Guanica is known for the Guanica Dry Forest, a UNESCO Biosphere Reserve, and the historic Guanica Lighthouse. The best time to travel to Guanica, United States, is from December to April, with average air temperatures around 75-85°F and water temperatures near 79-82°F. Sandee provides detailed maps, photos, and reviews from fellow beachgoers to help you Choose Your Beach™ and plan your perfect beach vacation!