Yellowstone (Montana entrance) in May

June through September gives you the full West Yellowstone experience. June can be muddy and cool, but wildlife is most active and crowds are manageable. July and August bring peak season chaos - book accommodations six months ahead and expect traffic delays. September is the sweet spot: warm days, cool nights, fewer crowds, and elk bugling season begins. Winter transforms the town into a snowmobile hub from December through March. Most restaurants and shops close, but the few that stay open create a cozy, local atmosphere. Spring (April-May) is unpredictable - some years bring snow, others bring early wildflowers.