Llanfaethlu, United Kingdom offers 1 beach perfect for sunbathing, surfing, swimming, and more. Llanfaethlu, Wales, United Kingdom, is known for its proximity to the scenic Church Bay and the historic St. Maethlu's Church. The best time to travel to Llanfaethlu, United Kingdom, is during late spring to early autumn (May to September) when the average air temperature ranges from 12°C to 18°C and the sea temperature is around 12°C to 16°C. Sandee provides detailed maps, photos, and reviews from fellow beachgoers to help you Choose Your Beach™ and plan your perfect beach vacation!