Knoxville weather is pretty mild. None of the four seasons come on very strongly, and neither the snow nor the summer heat will be much of a burden. There will be days you walk to class in a heavy coat and return to your dorm in a T-shirt, so you may want to start swapping summer clothes for some warmer ones during fall break. You will need to start spring semester with heavier clothing, such as sweaters and a thick coat, but you will probably be able to switch over to a light jacket just before Spring Break. The last month or so of classes is usually suitable for short sleeves and shorts. You will need a raincoat or sturdy umbrella year-round.
When, and if, it does snow, don't even think about driving somewhere unless you enjoy mass confusion and an occasional demolition derby (Johnny Knoxville would truly earn his name after attempting to drive through Knoxville amidst falling snow). Knoxville roads will be in a frenzy, and wrecks will be ever abundant. Make sure you finish your homework, however, because UT rarely cancels classes. UT students will pour out of the dorms and have massive snowball fights, which are guaranteed to create long-lasting memories. The fall is absolutely gorgeous, and the campus is beautiful when the leaves begin to fall. Many find the fall months to be most satisfying due to the comfortable temperature and nature. Spring comes with great excitement and is always beautiful on days it does not rain.