Fort Casey, United States offers 1 beach perfect for sunbathing, surfing, swimming, and more. Fort Casey is known for Fort Casey State Park and the Admiralty Head Lighthouse. The best time to travel to Fort Casey, United States, is during the summer months of June to August, when the average air temperature is around 65-75°F and the water temperature is approximately 50-55°F. Sandee provides detailed maps, photos, and reviews from fellow beachgoers to help you Choose Your Beach™ and plan your perfect beach vacation!