Badlands National Park in September

May through October gives you the best weather and all facilities open. Summer temperatures hit 100°F regularly, but the low humidity makes it bearable. Early morning and late afternoon offer the best light for photography and cooler hiking conditions. September and October are ideal – fewer crowds, comfortable temperatures, and the prairie grasses turn golden. Winter closes most facilities, but if you can handle the cold, you'll have the place to yourself. Spring can be muddy and unpredictable. Avoid holiday weekends if possible – this place gets surprisingly busy.