Harmon, United States offers 1 beach perfect for sunbathing, surfing, swimming, and more. Harmon, North Dakota, United States, is known for its proximity to the scenic Harmon Lake and the Harmon Lake Recreation Area. The best time to travel to Harmon, United States, is in late spring or early fall when the average air temperature is around 70°F and 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!