Annas Retreat, United States Virgin Islands offers 13 beaches perfect for sunbathing, surfing, swimming, and more. Annas Retreat, Saint Thomas, United States Virgin Islands, is known for its proximity to the popular Coral World Ocean Park and the scenic views from the nearby Mountain Top. The best time to travel to Annas Retreat, United States Virgin Islands, is from December to April, with average air temperatures around 77-82°F (25-28°C) and water temperatures around 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!