Lower Grand Lagoon, United States offers 1 beach perfect for sunbathing, surfing, swimming, and more. Lower Grand Lagoon, Florida, United States, is known for St. Andrews State Park and its proximity to the vibrant attractions of Panama City Beach. The best time to travel to Lower Grand Lagoon, United States, is from March to May, with average air temperatures ranging from 65°F to 80°F and water temperatures around 70°F. Sandee provides detailed maps, photos, and reviews from fellow beachgoers to help you Choose Your Beach™ and plan your perfect beach vacation!