Every upcoming Half Marathon around Key Biscayne, with start times, entry fees, finish-time stats from past editions, start-line maps, and the local run clubs to train with.
Racing in Key Biscayne means you are never far from open water. The Rickenbacker Causeway and its climb over the William Powell Bridge are the spine of running life here, and anyone who trains on the island knows exactly how many times they have crossed that bridge in a single long run. Early mornings on the causeway are busy; the mangroves and park paths at Crandon and Bill Baggs stay quieter.
The climate shapes everything. Miami's humidity means most runners are out at first light or after sunset, and the fall race calendar reflects that instinct to wait for slightly more forgiving air. When a race does arrive, the backdrop of Biscayne Bay and the lighthouse at Cape Florida makes for a setting that is genuinely hard to match.
How we calculate these stats: RunSesh calculates these figures from the most recent published results of past editions, sourced from RunSignup. We show aggregates only: field size, winning and median times, and the cutoff. We never publish individual finisher tables. Last updated Jul 27, 2026.
Common Questions About Running a Half Marathon in Key Biscayne
When is the best time to find a half marathon in Key Biscayne?
Fall - September through November - is the busiest stretch, with 12 races on the calendar. If you are targeting a specific window, January is the single busiest month with 4 races. February is the quietest, with 2. Winter overall brings 10 races, summer 6, so there is something in every season.
What does it cost to enter a half marathon here?
Entry fees sit at $30, and that is consistent across the races that have published pricing. None of the races currently show a scheduled price increase, so there is no urgency penalty for registering a little later, though that can always change.
Will I get a shirt at these races?
All 28 races say they give a shirt. None of them mention a medal, so if hardware matters to you, check directly with the race before you sign up.
Is this a good spot for a first half marathon?
Key Biscayne's terrain is mostly flat, which suits someone building toward a first 13.1. The William Powell Bridge is the one significant climb local runners talk about, but the island's courses have not published elevation details. Every race here also offers a 5K and a 10K on the same day, so you can step up distances at the same event as you build confidence.
How do finishing times at these races compare to what I might expect?
None of the 28 half marathons here have published finish-time results, so there is no field data to draw on. If you want a sense of where you might land in the field, the race organizers are your best source.
