Carbondale, United States offers 2 beaches perfect for sunbathing, surfing, swimming, and more. Carbondale, Illinois, United States, is known for Southern Illinois University and its proximity to the Shawnee National Forest. The best time to travel to Carbondale, United States, is in late spring (May), when the average air temperature is around 70°F (21°C) and water temperature in nearby lakes is approximately 65°F (18°C). Sandee provides detailed maps, photos, and reviews from fellow beachgoers to help you Choose Your Beach™ and plan your perfect beach vacation!