Cardiff, United Kingdom offers 2 beaches perfect for sunbathing, surfing, swimming, and more. Cardiff is known for Cardiff Castle, Principality Stadium, and the National Museum Cardiff. The best time to travel to Cardiff is from June to August, with average air temperatures around 18°C (64°F) and water temperatures near 16°C (61°F). Sandee provides detailed maps, photos, and reviews from fellow beachgoers to help you Choose Your Beach™ and plan your perfect beach vacation!