Cagliari, Italy offers 19 beaches perfect for sunbathing, surfing, swimming, and more. Cagliari is known for its historic Castello district, Poetto Beach, and the Roman Amphitheatre. The best time to travel to Cagliari, Italy, is from May to June, when the average air temperature is around 24°C (75°F) and the water temperature is approximately 20°C (68°F). Sandee provides detailed maps, photos, and reviews from fellow beachgoers to help you Choose Your Beach™ and plan your perfect beach vacation!