Regardless of the time of day you decide to fly, the ticket price will remain around the same. Book flights from Koh Samui to Chicago as you normally would.
Related info for your journey
Useful info, stats and facts about Koh Samui to Chicago flights.
Located just 3.3 km from the city centre, Ko Samui is the airport most travellers will use when flying to Chicago from Koh Samui. Booking flights from Ko Samui (USM) to Chicago should be relatively easy as there are 0 daily outbound flights to Chicago from 0 different airlines.
USM stands for Ko Samui Airport, while ORD stands for Chicago O'Hare Intl Airport. These codes are often called IATA codes, a set of identifiers established by IATA (International Air Transport Association) that is widely used by airlines and the aviation industry. Chicago Midway Airport (MDW), Chicago Greater Rockford Airport (RFD) are other airports near this flight route and their unique identifiers/IATA codes.