Lyme, United States offers 1 beach perfect for sunbathing, surfing, swimming, and more. Lyme, New Hampshire, United States, is known for the Dartmouth Skiway and its proximity to the Appalachian Trail. The best time to travel to Lyme, United States, is in late spring (May to June) when the average air temperature is around 60-70°F and the water temperature is approximately 50-60°F. Sandee provides detailed maps, photos, and reviews from fellow beachgoers to help you Choose Your Beach™ and plan your perfect beach vacation!