San Agustinillo, Mexico offers 2 beaches perfect for sunbathing, surfing, swimming, and more. San Agustinillo is known for its beautiful beaches and proximity to the Mazunte Turtle Center. The best time to visit San Agustinillo, Mexico, is from November to April, with average air temperatures around 80°F (27°C) and water temperatures near 82°F (28°C). Sandee provides detailed maps, photos, and reviews from fellow beachgoers to help you Choose Your Beach™ and plan your perfect beach vacation!