The tallest dunes in North America stand at the center of a diverse landscape of grasslands, wetlands, conifer and aspen forests, alpine lakes, and tundra, with starry skies on moonless nights and walks across the dunes under bright full moonlight. Temperatures remain relatively cool year round because of the high elevation, and conditions are most often calm, though winds can arise, especially in spring and during storm fronts. Daytime temperatures feel warmer because of intense high-altitude sunlight and a scorching mid-day summer sand surface, making morning or evening the best times to explore the dunes during summer, while nights are cool in summer and frigid in winter.