The dates when Chicago hotels fill up and prices jump: Lollapalooza, the Chicago Marathon, big stadium concerts and large McCormick Place conventions. Check here before you pick your travel dates.
During Lollapalooza weekend in summer, the Chicago Marathon in October, big Soldier Field and Wrigley Field concerts and the largest McCormick Place conventions. Winter is cheapest.
Avoid the dates on this page, and prefer Sunday to Thursday nights; weekends cost more almost every week of the year.
Dates come from the organizers; we check them regularly.