Island Harbour, Anguilla offers 5 beaches perfect for sunbathing, surfing, swimming, and more. Island Harbour, Anguilla, is known for Scilly Cay, a small island restaurant famous for its fresh seafood and vibrant atmosphere. The best time to travel to Island Harbour, Anguilla, is from December to April, with average air temperatures around 77-82°F (25-28°C) and water temperatures about 79-82°F (26-28°C). Sandee provides detailed maps, photos, and reviews from fellow beachgoers to help you Choose Your Beach™ and plan your perfect beach vacation!