Rio Nuevo, Jamaica offers 7 beaches perfect for sunbathing, surfing, swimming, and more. Rio Nuevo, Saint Mary, Jamaica, is known for its historical significance as the site of the last battle between the British and Spanish in Jamaica. The best time to travel to Rio Nuevo, Jamaica, is from December to April, with average air temperatures around 77-86°F (25-30°C) and water temperatures near 81°F (27°C). Sandee provides detailed maps, photos, and reviews from fellow beachgoers to help you Choose Your Beach™ and plan your perfect beach vacation!