Next edition: 31 January 2027
The only hills are bridges, and the median is still 4:40: what decides this race is not the profile, it is 80% average humidity arriving exactly at the shadeless bridge at mile 16.
Figures from 2026.
A small, slow field, and worth knowing before you enter: 3,250 finishers in 2026, a 4:40:34 median, and 21 people under three hours — 0.65%. 2025 had 2,935 finishers, a 4:44 median and eleven sub-3. For scale, a fast European marathon puts that figure above 15%. If you are chasing a time, this is not the race; if you are finishing a first marathon with a generous clock, it is. The weekend moves 18,000 runners, but the marathon is the small part of it.
Two gates, and the first one is the one that surprises people.
Mile 12.8 (km 20.6) in 3 hours 30. Miss it and you are diverted onto the half-marathon course. It is not a withdrawal — your race simply becomes a different race.
7 hours from the last wave for the full, about 10:00 per kilometre, with the finish open until 14:00. Chip time, not gun. After seven hours support is pulled and the sweep vehicle ends your race; medals and official times only inside that window.
Sea-level loop starting and finishing on Biscayne Boulevard. No real elevation except the bridges: MacArthur, Venetian and the Rickenbacker out-and-back.
The sources do not resemble each other: RunReady measures 129 m in 2026, RunDida gives 77, Garmin about 55, and the organiser simply says there are no noticeable changes except the bridges. We do not average four numbers that are measuring different things.
Start at 601 Biscayne Boulevard beside the Kaseya Center; finish in Bayfront Park. It shares 20.8 km with the half.
km 0.4. MacArthur Causeway. The first bridge arrives almost immediately, in the dark: half a kilometre at 3.3%, then a 5.2% descent. The steepest climb of the day is in the first kilometre.
km 4. Onto Miami Beach. A gentler ramp.
km 13-18. Venetian Causeway. A small rise in the closing portion, then back to the mainland.
km 24-28. The Rickenbacker out-and-back. The second real climb, and the one with no shade at all.
km 21 and 41. The South Miami Avenue bridge. Short both times.
Almost every account of this race names the same place and the same cause: the Rickenbacker, between km 26 and 29, and the humidity.
A 2025 first-timer: *"coming back off the Rickenbacker Causeway (IYKYK) at mile 17"* — cramping, walking the back half. Another in 2026: *"blew up on the out and back around 18"*. A third, in 2024, puts it in the same place: *"at mile 16 we entered a bridge where there was no shade"*, at 29 °C and 95% humidity. A coach who lives there says it without metaphor: your biggest hill will be miles 15 and 16, out over the Rickenbacker.
The humidity is not a bad-year anecdote, it is the constant. The four-year average humidity at the start is 80%, which puts Miami among the ten most humid marathons in the United States. The 6:00 a.m. start is dark and pleasant; the second half is run with the sun up and on open bridges.
The field numbers confirm it: the median here is 4:40 and six runners in a thousand break three hours. This is not a slow course. It is a slow climate.
January in Miami, a 6:00 a.m. start in the dark. Four-year average start humidity of 80%; 2026 was run above 21 °C with accounts of 94% humidity. Sunrise arrives over the MacArthur and the second half is in full sun.
6:00 a.m., and nobody starts after 7:00. Corrals open at 5:00 and go off in blocks through 6:45.
General registration opens 1 August of the preceding year. No lottery, no qualifying time: first come, with a combined 18,000 cap across the marathon and the half.
First come, until the cap is reached
USATF-certified. A Boston-qualifying course.
Corrals are preassigned by bib, with no time to accredit. They open at 5:00 and go off in blocks: ABCD at 6:00, EFG at 6:15, HI at 6:30, KL at 6:45. Gear check is three blocks south, past Bayside.
The cap goes fast: 2026 opened on 1 August 2025 and the marathon closed somewhere between 11 and 15 August — under two weeks. Transfers and deferrals exist for a fee; there are no refunds.
Entry and conditions verified on 5 September 2026. The organiser is the source for any date that moves.
If you train in the southern hemisphere or the tropics, Miami asks for little you are not already doing. If you train through a winter, it asks for almost everything.
Humid-heat acclimatisation, and it is the only thing that really matters. The limiter here is not threshold or volume, it is the ability to shed heat into saturated air. It takes ten to fourteen sessions in hot conditions across the three weeks beforehand — overdressed if necessary — because the adaptation comes quickly and is lost just as quickly.
A fluid plan rehearsed at race pace, not on easy runs. At 80% humidity sweat does not evaporate and thirst lies. You settle this in advance by measuring what you lose on a long run in heat, not by improvising at km 25.
And practise running down bridges. Miami's climbs are short, but the MacArthur descends at 5.2% inside the first kilometre, in the dark, on cold legs. Put a short descent early in a long run so the movement is not new.
On the 3:30 gate at mile 12.8: if your realistic target is near five hours, that minimum pace is the number the plan is built around, and it leaves room — but it is worth knowing before the start rather than at the diversion.
There is still room: the 18 weeks block starts on 27 September 2026. Until then the work is base — easy volume and consistency — not this plan.
Three levels, two durations, heart-rate based. Choose by the volume you can sustain, not the volume you would like to run.
Entries closed Entries are not open right now: opens 1 August 2026. These blocks still apply if you already have a place, or if you are chasing the qualifier.
You do not need to be exactly 12 or 18 weeks out. A specific block is not started from zero — you arrive at it already active, and these plans are the last part of that road.
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Eighty per cent average humidity and a shadeless bridge at mile 16: two things a calendar plan cannot see, and they decide your race.
A calendar plan does not know which corral you drew, how last month went, or what to do when the week falls apart. If what you have just read about this race changes your approach, that is a conversation, not a PDF.
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