Long Neck, United States offers 1 beach perfect for sunbathing, surfing, swimming, and more. Long Neck, Delaware, United States, is known for its proximity to the popular tourist destination of Rehoboth Beach. The best time to travel to Long Neck, United States, is in late spring or early fall when the average air temperature is around 70°F and the water temperature is approximately 65°F. Sandee provides detailed maps, photos, and reviews from fellow beachgoers to help you Choose Your Beach™ and plan your perfect beach vacation!