Check the weather forecast for your intended dates of travel. Chicago winters are the fiercest in the country. The wind chill can drop temperatures deep into the negative. The summers can be hot and humid.
Pack business attire appropriate to your line of work. Choose lighter-weight materials for the summer months. Women wear hose with suits - despite the summer heat - and tights for warmth in the winter.
Think casual for taking in the sights and sounds of the city. Jeans and khakis are appropriate for winter; shorts befit the summer months. T-shirts are a staple.
Pack a very heavy winter coat, long underwear, sweaters, boots, socks, gloves, a scarf and a hat if you plan to be there between December and March. Wear rubber-soled shoes to avoid slipping on ice and snow.
Choose lightweight fabrics such as cotton and linen for summer visits, as these natural fibers will breathe in the heat. Pair summer attire with comfortable walking shoes or sandals.
Remember black will hide dirt and absorb heat; white and ivory will betray dirt but keep you cool.
Stash a swimsuit in your bag in case you have the opportunity to take a dip in Lake Michigan during the summer months.
