Chicago's major events, ranked by crowd impact
Every event here is verified by a person, dated from its own organiser, and measured against Chicago's day-by-day crowd forecast — so they can be ranked on one scale. See the city, day by day →
#1 Bank of America Chicago Marathon →
The Marathon is the busiest of Chicago's 1 verified major events — its day reads Busy, busier than 83% of Chicago's year.
The 2026 Bank of America Chicago Marathon in Chicago runs 11 Oct 2026, confirmed; expect Busy days — busier than 83% of Chicago's year. (Avoid-Crowds, as of 2026-08-30; recomputed nightly.)
Disclaimer — event dates can change; expected dates are labelled and can move.