Spirit Lake, United States offers 3 beaches perfect for sunbathing, surfing, swimming, and more. Spirit Lake is known for the Iowa Great Lakes, including West Okoboji Lake and Arnolds Park Amusement Park. The best time to travel to Spirit Lake, United States, is during the summer months of June to August, when the average air temperature is around 75°F (24°C) and the water temperature is approximately 70°F (21°C). Sandee provides detailed maps, photos, and reviews from fellow beachgoers to help you Choose Your Beach™ and plan your perfect beach vacation!