South Dakota has four distinct seasons of weather, ranging from cold winters to hot summers. Temperatures can reach over 100*F in the summer and average below freezing in the winter. Average humidity across the state ranges from semi-arid in the northwest to semi-humid in the southeast. Summers can bring severe weather in the form of thunderstorms, but most days are clear and sunny.

Summer (Memorial Day/late May to Labor Day/early September) is optimal for visiting many of the attractions in the state. However, weather can be mild in both the spring and fall months, and visiting outside of the summer season offers less traffic and opportunities for seeing spring’s first blossoms or fall’s brilliant foliage. Very cold winter weather alternates with milder spells, and snowfall can be prevalent. December through early March is the best time to take advantage of several downhill ski areas, more than 1,500 miles of snowmobiling trails, ice fishing and other winter sports and activities.

During the summer months, South Dakota experiences approximately 15-16 hours of daylight each day. During the winter months, it averages to 9-10 hours of daylight. South Dakota observes two different time zones: Central Time in most areas of the state east of the Missouri River, and Mountain Time in areas west of the Missouri River.