San Juan de la Costa, Chile offers 6 beaches perfect for sunbathing, surfing, swimming, and more. San Juan de la Costa is known for its beautiful beaches and the indigenous Huilliche culture. The best time to travel to San Juan de la Costa, Chile, is during the summer months of December to February, when the average air temperature is around 68°F (20°C) and the water temperature is approximately 59°F (15°C). Sandee provides detailed maps, photos, and reviews from fellow beachgoers to help you Choose Your Beach™ and plan your perfect beach vacation!