Kassopei, Greece offers 7 beaches perfect for sunbathing, surfing, swimming, and more. Kassopei, Ionian Islands, Greece, is known for its picturesque beaches and traditional Greek architecture. The best time to travel to Kassopei, Greece, is from May to September, with average air temperatures ranging from 75°F to 85°F and water temperatures from 72°F to 79°F. Sandee provides detailed maps, photos, and reviews from fellow beachgoers to help you Choose Your Beach™ and plan your perfect beach vacation!