Opcina Bol, Croatia offers 4 beaches perfect for sunbathing, surfing, swimming, and more. Opcina Bol, Istria, Croatia, is known for its stunning Zlatni Rat beach and vibrant windsurfing scene. The best time to travel to Opcina Bol, Croatia, is from June to September, when the average air temperature is around 75°F (24°C) and the sea temperature is approximately 75°F (24°C). Sandee provides detailed maps, photos, and reviews from fellow beachgoers to help you Choose Your Beach™ and plan your perfect beach vacation!