IRONMAN 70.3 Cozumel
Course breakdown, historical weather, field analysis, and pacing notes.
A fast, flat course in Cozumel
Cozumel, Mexico · September 20, 2026
IRONMAN 70.3 Cozumel takes place in Cozumel, Mexico on September 20, 2026. The half-distance course covers a 1.88 km swim, 89.8 km bike, and a 20.8 km run. Heat management and hydration strategy will be critical on race day.
- Swim
- 1.9 km
- Ocean
- Bike
- 89.8 km
- ↑164m · Flat
- Run
- 20.8 km
- ↑11m · Flat
- Air Temp
- 23–32°C
- Water Temp
- 27°C
- Wind
- 12 km/h
- S
Swim Course
Warm water swim over 1.88 km
Athletes face a 1.88 km swim in ocean conditions. Water temperatures are above the wetsuit-legal threshold, meaning a non-wetsuit swim.
- Ocean swim
- 27°C average water temperature
- 3 sharp turns
Bike Course
A fast, flat 89.8 km ride
The bike course covers 89.8 km across flat terrain.
- 0.0 m/km average gradient
- 1 U-turn
- 31 sharp turns
- Flat terrain profile
Run Course
Fast, flat 2-lap run course
The run covers 20.8 km with 12m of climbing. Athletes complete 2 laps, so crowd support and mental pacing strategies play a big role.
- 12m total elevation gain
- 0.6 m/km average gradient
- 2 U-turns
- 20 sharp turns
- 2 laps
- Flat terrain profile
Race Day Conditions
Heat management will make or break your race
Based on historical averages, expect temperatures around 28°C on race day. Ice, sponges, and a conservative opening pace will pay dividends in the run. Winds average 12 km/h.
Race Field Insights
How the Field Performs
Aggregated from 6,157 finishers (2022–2025)
- Total Starters
- 6,597
- Finishers
- 6,157
- DNF Rate
- 6.4%
- Years of Data
- 2022–2025
- Median Finish
- 6h 12m
Finish Time Distribution
How the Median Finisher Spends Race Day
What Each Pace Looks Like
Fast | Solid | Median | Back of Pack | Slow (P90) | |
|---|---|---|---|---|---|
| Swim | 30m 35s | 34m 12s | 38m 45s | 44m 55s | 50m 59s |
| Bike | 2h 32m | 2h 43m | 2h 56m | 3h 11m | 3h 27m |
| Run | 1h 49m | 2h 04m | 2h 23m | 2h 45m | 3h 06m |
| Finish | 5h 07m | 5h 37m | 6h 12m | 6h 50m | 7h 27m |
Related reading
Race Day Weather and What It's Really Doing to Your Pacing Plan
Performance starts dropping over 22°C and humidity makes it worse. How heat compounds across the bike and run — and why the bike hides it.
Read postYour Race Plan Isn't Generic — Why Course Intelligence Changes Everything
Same FTP on two different courses produces two completely different races. Elevation, wind, and shelter change what every watt is worth.
Read postPlan IRONMAN 70.3 Cozumel with Keiro
Get a complete pacing strategy for every discipline — built from this course, forecast weather, and your fitness.
Independent analysis. KeiroLabs is not the event organizer and is not affiliated with the race organizer.