Southern Islands, Singapore offers 3 beaches perfect for sunbathing, surfing, swimming, and more. Southern Islands, South West Region, Singapore, is known for Sentosa Island, Universal Studios Singapore, and the S.E.A. Aquarium. The best time to visit the Southern Islands of Singapore is from February to April, with average air temperatures around 27-31°C (81-88°F) and water temperatures approximately 28-30°C (82-86°F). Sandee provides detailed maps, photos, and reviews from fellow beachgoers to help you Choose Your Beach™ and plan your perfect beach vacation!