The best time of year to visit the Great Sand Dunes National Park and Preserve is during the spring and fall seasons. During these times, the weather is more moderate with cooler temperatures and less wind, making it more enjoyable to explore the sand dunes. Spring, specifically April and May, is a great time to visit as the snowmelt from the surrounding mountains creates a shallow creek that flows through the sand dunes, providing a unique and picturesque landscape. Summer can also be a popular time to visit the Great Sand Dunes, especially for families on vacation. However, it is important to note that the sand can become scorching hot during the peak summer months, making it uncomfortable to walk on without proper footwear. Additionally, thunderstorms are common during the summer, so it is important to be prepared for sudden weather changes. Winter is the least popular time to visit the Great Sand Dunes due to the cold temperatures and potential for heavy snowfall. However, if you are a fan of winter sports, such as snowboarding or sledding, the sand dunes offer a unique opportunity to enjoy these activities. Just make sure to dress warmly and be aware of the potential hazards that come with winter conditions.