Sibenik, Croatia offers 7 beaches perfect for sunbathing, surfing, swimming, and more. Sibenik is known for the UNESCO World Heritage Sites of St. James Cathedral and St. Nicholas Fortress. The best time to travel to Sibenik, Croatia, is from May to September, when the average air temperature ranges from 20°C to 30°C (68°F to 86°F) and the sea temperature is around 22°C to 25°C (72°F to 77°F). Sandee provides detailed maps, photos, and reviews from fellow beachgoers to help you Choose Your Beach™ and plan your perfect beach vacation!