You will find that American college students (and professors too) dress informally for classes and daily activities. Blue jeans are common. Americans also entertain informally, so formal attire is almost never required.
The climate in Iowa requires a variety of clothing. Students are expected to attend class even on days when it is raining or snowing, or very hot and humid.
You will probably want the following items. You may bring them with you, or purchase them in Des Moines after you arrive. It is wise to be as prepared as possible for the season in which you arrive, in case you can not shop immediately. (Approximate U.S. prices for some items are listed.)
A warm coat, stocking cap, scarf and mittens for winter (about US $100.00)
Warm sweaters and pants (for men and women) in winter (about US $25.00 - $50.00 each)
Boots or warm shoes for walking in winter snow (about US $40.00)
An umbrella (US $10.00); Rain coat or jacket (US $40 - $60.00)
Blue jeans (US $25 - $45.00)
Lightweight clothes for summer...sandals, shorts, and short-sleeved shirts are acceptable for men and women, even in class. (Prices vary)
A sport coat for men (US $100.00 or more), a nice dress for women (US $40.00 or more), may be desirable for special occasions.
One outfit of professional attire for employment purposes or special academic events (such as award recognition ceremonies).
Both men and women may also want to have traditional clothing from home for special occasions like “International Night”.