Lerna, Greece offers 2 beaches perfect for sunbathing, surfing, swimming, and more. Lerna is known for the archaeological site of the Lernaean Hydra myth and the House of the Tiles. The best time to travel to Lerna, Greece, is from May to September, with average air temperatures ranging from 70°F to 85°F and water temperatures from 70°F to 80°F. Sandee provides detailed maps, photos, and reviews from fellow beachgoers to help you Choose Your Beach™ and plan your perfect beach vacation!