Agios Gerasimos, Greece offers 1 beach perfect for sunbathing, surfing, swimming, and more. Agios Gerasimos, Attica, Greece, is known for the Monastery of Agios Gerasimos, a significant religious site dedicated to Saint Gerasimos. The best time to travel to Agios Gerasimos, Greece, is from May to September, with average air temperatures ranging from 75°F to 85°F and water temperatures around 73°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!