Slievebawn, Ireland offers 1 beach perfect for sunbathing, surfing, swimming, and more. Slievebawn is known for the Slievebawn Castle and the annual Ulster Folk Festival. The best time to travel to Slievebawn, Ireland, is from May to September, with average air temperatures ranging from 50°F to 65°F and water temperatures around 55°F. Sandee provides detailed maps, photos, and reviews from fellow beachgoers to help you Choose Your Beach™ and plan your perfect beach vacation!