IRONMAN 70.3 Cairns
Course breakdown, historical weather, and field analysis.
Tropical Queensland — Great Barrier Reef coast racing
Cairns, Australia · June 14, 2026
IRONMAN 70.3 Cairns takes athletes to Australia's tropical north. A sea swim off the Cairns Esplanade, a bike through the tropical hinterland, and a run along the waterfront. Cairns offers warm water, challenging terrain, and the unique atmosphere of tropical Australian racing.
- Swim
- 1.9 km
- Ocean
- Bike
- 89.8 km
- ↑508m · Rolling
- Run
- 21.7 km
- ↑22m · Flat
- Air Temp
- 15–26°C
- Water Temp
- 24°C
- Wind
- 20 km/h
- NW
Swim Course
Tropical sea swim off the Cairns Esplanade
The swim takes place in the warm Coral Sea waters off the Cairns Esplanade. Water temperatures in June (Australian winter) are still warm at 23–25°C — typically non-wetsuit legal. The calm tropical waters and waterfront setting make for a pleasant swim, though marine stinger nets provide protection during the warmer months.
- Warm Coral Sea waters — likely non-wetsuit legal
- Cairns Esplanade waterfront start
- Calm tropical conditions
- Marine stinger protection in place
Bike Course
Rolling roads through the tropical hinterland
The bike course heads into the rolling hills behind Cairns. The tropical hinterland features lush vegetation, sugar cane fields, and moderate climbing. The route is a genuine test — the hills are real, and the tropical warmth adds to the effort. The scenery is distinctly far-north Queensland — tropical rainforest, palm plantations, and volcanic red earth.
- Rolling hills through tropical hinterland
- Moderate climbing in warm conditions
- Lush tropical scenery — rainforest and sugar cane
- Warm temperatures add to the effort
Run Course
Waterfront run along the Cairns Esplanade
The run follows the Cairns Esplanade — the city's waterfront promenade. The terrain is flat and the tropical setting provides palm trees for some shade. The Cairns community turns out to support, and the relaxed tropical atmosphere makes for a distinctive race experience.
- Flat waterfront esplanade running
- Palm trees provide partial shade
- Tropical Cairns atmosphere
- Strong local community support
Race Day Conditions
Tropical Queensland — warm, humid, but not extreme
June in Cairns is the dry season — tropical but not at its most extreme. Air temperatures range from 18–26°C with moderate humidity. This is one of the more comfortable times to race in the tropics, as the wet season heat has passed. Morning temperatures can be pleasant, with warmth building through the day.
Race Field Insights
How the Field Performs
Aggregated from 4,128 finishers (2022–2025)
- Total Starters
- 4,287
- Finishers
- 4,128
- DNF Rate
- 3.6%
- Years of Data
- 2022–2025
- Median Finish
- 5h 51m
Finish Time Distribution
How the Median Finisher Spends Race Day
What Each Pace Looks Like
Fast | Solid | Median | Back of Pack | Slow (P90) | |
|---|---|---|---|---|---|
| Swim | 29m 08s | 32m 00s | 35m 44s | 39m 56s | 44m 44s |
| Bike | 2h 29m | 2h 42m | 2h 59m | 3h 17m | 3h 38m |
| Run | 1h 36m | 1h 48m | 2h 04m | 2h 24m | 2h 44m |
| Finish | 4h 46m | 5h 15m | 5h 51m | 6h 34m | 7h 15m |
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 Cairns 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.