Dassia, Greece offers 2 beaches perfect for sunbathing, surfing, swimming, and more. Dassia, Ionian Islands, Greece, is known for its beautiful beaches and vibrant resort atmosphere. The best time to travel to Dassia, Greece, is from June to September, with average air temperatures around 80°F (27°C) and water temperatures about 77°F (25°C). Sandee provides detailed maps, photos, and reviews from fellow beachgoers to help you Choose Your Beach™ and plan your perfect beach vacation!