Chicago Marathon
Race Day Weather
Cool morning, gradual warming
Runners will face temperatures starting at 58°F and rising to 68°F, with an average humidity of 77%. Light winds will provide a tailwind during the first half, shifting to headwinds from miles 9 to 23, making those sections the most challenging. Runners should consider starting conservatively and adjust pacing as temperatures rise, especially in the latter part of the race.
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Race Info
The Chicago Marathon starts and finishes in Grant Park, looping through 29 Chicago neighborhoods and crossing the Chicago River six times. The flat, fast course is a Boston qualifier and has produced seven marathon world records, most recently Ruth Chepng'etich's 2:09:56 women's mark in 2024. It's one of the seven Abbott World Marathon Majors, held every year on the second Sunday of October.
