
From the Organizer
The 18th Annual F^3 Lake Half Marathon & 5k is Chicago's Original Winter Half Marathon. Each year, thousands of runners flock to this community-built event, gathering in the warmth of Soldier Field's United Club before tackling wind & weather along a lakefront course that features splits every 5km. A must for anyone preparing for a spring marathon or just resolving to stay fit throughout the new year. F^3 sold out in 2016-2020 and 2023-present.
Every registrant will once again receive one of our great hoodies and a medal! We will return to the warm confines of Soldier Field's United Club! The UC opens at 8 a.m. Gear check is available. The half marathon starts at 10:01 a.m. and consists of self-seeded waves in quick succession. The 5k is scheduled for 10:29 a.m. Courses close at 1:30 p.m.
After the race, head to Weathermark Tavern for the afterparty! 1503 S. Michigan Ave. Free participant photos are always uploaded to flashframe.io
Events
Weather
It's too far out for a forecast, so here's what weather on this date is normally like in the area. A race day forecast will replace this as race week approaches.
Typical High
32°
Typical Low
20°
Based on US Climate Normals data from Chicago Northerly Is, 3 mi from the venue.
Host City
Population
2,707,648
as of 2023
Elevation
594 ft
Nearest Airport
MDW
Chicago Midway International Airport · 6 mi
Time Zone
Central Time
From Endurance Grid
A big city race. Expect multiple lodging options and plenty to do the day before.
Race Location
Your Next Start Line
Every finish line starts with a single decision. Claim your spot at 18th Annual F^3 Lake Half Marathon & 5k, put it on the calendar, and turn “someday” into a start date.
236
Days to train
Coming Up
Freedom Bike Ride
Less than a mile away
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Bagel Run 5K/10K/13.1 CHICAGO/EVANSTON
Less than a mile away
From Endurance Grid
Endurance Grid is here to help you understand the sport, decide if it's the right fit, and learn how to prepare. For course distances, logistics, and race-day specifics, always defer to the race organizer's event page.
The half marathon is the distance where you find out what you're actually made of. Long enough to demand real preparation. Short enough that it doesn't consume your life to train for it. Most people who run their first half describe it as the race that changed their relationship with what they're capable of. Once you cross this finish line, the bar moves. That's not a warning — that's the point.
Race day energy varies by event size, but the finish line feeling is the same regardless. Big races keep the noise going the whole way. Smaller races give you stretches where it's just you and the miles — and that solitude becomes its own kind of fuel.
The half marathon rewards people who show up for the boring training miles.
How long to train: 10–14 weeks. If you're already running consistently, 10 weeks of structured buildup is enough. If you're building from a casual base, give yourself 14.
From 5K to marathon, running races are the most accessible entry point into endurance sport. There's a distance for every fitness level and a community at every start line.
Frequently Asked Questions (FAQs)
18th Annual F^3 Lake Half Marathon & 5k
Jan 30, 2027