Lagonisi, Greece offers 1 beach perfect for sunbathing, surfing, swimming, and more. Lagonisi is known for the luxurious Grand Resort Lagonissi and its beautiful beaches along the Saronic Gulf. The best time to travel to Lagonisi, Greece, is from late May to early October, 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!