Which airport code represents Champaign/Urbana, Illinois?

The airport code for Champaign/Urbana, Illinois, is CMI, which stands for University of Illinois Willard Airport. Each airport has a unique three-letter IATA code assigned to it, and CMI specifically corresponds to this airport, facilitating identification and use in airline ticketing and baggage handling.

The codes CHS, SLU, and CCS represent airports in different locations: CHS is for Charleston International Airport in South Carolina, SLU is for Saint Lucia, and CCS is for Simon Bolívar International Airport in Caracas, Venezuela. These alternatives do not relate to Champaign/Urbana, which is why they are not the correct answer.