Chicago, Illinois, also known as "The Windy City" has a population of roughly 2.7 million residents. It is the largest city in the state, and the third most populated city in the entire United States. The city is located in Northeastern Illinois at the tip of Lake Michigan. Summers in Chicago and warm and humid, with mild spring and fall weather. Visitors have several options for getting in and out of the city. The Chicago O'Hare Airport is the largest airport in the city. Travelers also have the option of using the AmTrack service, taxi cabs, bicycling, the public bus system, and cheap car rentals. The Port of Chicago is also available for water transport.