Agia, Greece offers 5 beaches perfect for sunbathing, surfing, swimming, and more. Agia, Epirus, Greece, is known for the Acheron River, which is associated with Greek mythology as the river of woe. The best time to travel to Agia, 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 78°F. Sandee provides detailed maps, photos, and reviews from fellow beachgoers to help you Choose Your Beach™ and plan your perfect beach vacation!