Oles often like to exaggerate when they talk about their winters. It's a hobby students have. Honestly, though, even in Southern Minnesota, it gets really, really cold. Students from warmer climates will probably freak out a little during their first winter, but it gets easier as time goes on. There are very few big blizzards, and classes rarely have to be canceled due to snow, but it can happen. Mostly though, Olaf's amazing sledding opportunities make it a great place to be in the winter.
As far as clothes go, for midwinter, the real trick to staying warm without looking like you're entered in a dog-sledding race is layering. A shirt and light jacket or sweater topped off with a wool coat, scarf, and mittens is enough to get you from your room to class and back again without too much trouble. Of course, it isn't cold all the time. Autumn is pleasant in the day and a little brisk in the evening. When the trees turn and the ivy goes all fire red, the campus is stunningly beautiful. The tail end of the year is typically rainy and in the low to mid 60s. There are, however, a few weeks in April and May when it gets much warmer and sunnier. If you decide to stay during the summer, expect lots of heat and humidity. And remember, up on this hill, it really is always windy.