Illinois is the most populous and demographically diverse Midwestern state and the fifth most populous state in the nation. It has industrial cities, great agricultural productivity in central and western Illinois, and natural resources like coal, timber, and petroleum in the south.
More than half of the population of Illinois resides in the northeastern corner of the state, primarily within the city of Chicago and the surrounding area. The city of Rockford is the second largest metropolitan area and the state's third largest city, Peoria, is approximately 75 miles (121 km) northwest of Chicago. Springfield is the state capital.
Most of Illinois has a humid continental climate, with hot, humid summers and cool to cold winters.