Astros Beach, Greece offers 3 beaches perfect for sunbathing, surfing, swimming, and more. Astros Beach, Peloponnese, Greece, is known for its picturesque harbor, the medieval Astros Castle, and the beautiful sandy beaches along the Argolic Gulf. The best time to travel to Astros Beach, Greece, is from June to September, with average air temperatures around 77°F (25°C) and water temperatures about 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!