South Dakota experiences all four seasons: Spring, Summer, Fall & Winter.  Spring generally begins late-March and goes through mid-June.  Dress in layers and with a jacket, as cool temperatures can still pop up or evenings cool down.  Summer begins mid-June and continues through mid-September.  Shorts, sandals, and short-sleeved shirts are the norm, and if you are planning to spend much time outdoors don't forget the sunscreen!  Fall begins mid-September and continues through November, and Winter generally runs from December through mid-March.  For Fall temperatures, again plan for layers as well as a jacket; for winter make sure to have your winter coat, hat and gloves!