Diamond Valley, Barbados offers 2 beaches perfect for sunbathing, surfing, swimming, and more. Diamond Valley, Saint Philip, Barbados, is known for its picturesque beaches and tranquil coastal scenery. The best time to travel to Diamond Valley, Barbados, is between December and April, with average air temperatures around 27°C (81°F) and water temperatures near 26°C (79°F). Sandee provides detailed maps, photos, and reviews from fellow beachgoers to help you Choose Your Beach™ and plan your perfect beach vacation!