18th Annual F^3 Lake Half Marathon & 5k 2027

F^3 Lake Half Marathon & 5k is a winter running event in Chicago, beginning inside Soldier Field's United Club before runners head out to the lakefront. It features both a half marathon and a 5k, attracting thousands of participants. This event addresses two Chicago-specific needs: a challenging cold-weather test for spring marathon preparation and a structured method to maintain activity post-New Year. The course runs along the lakefront, with wind and winter conditions intentionally part of the challenge. The half marathon course includes splits at every 5km. Participants start in self-seeded waves, and the race is open to individuals aged 12 and older. All registrants receive a hoodie and a medal. Beyond standard race amenities, prize money is awarded to top overall and masters finishers, free participant photos are published post-race, and the post-race gathering takes place at Weathermark Tavern on South Michigan Avenue.