Yallahs, Jamaica offers 1 beach perfect for sunbathing, surfing, swimming, and more. Yallahs, Saint Thomas, Jamaica, is known for the Yallahs River and its proximity to the Blue Mountains. The best time to travel to Yallahs, Jamaica, is from December to April, with average air temperatures around 80°F (27°C) and water temperatures near 82°F (28°C). Sandee provides detailed maps, photos, and reviews from fellow beachgoers to help you Choose Your Beach™ and plan your perfect beach vacation!