London T100 Triathlon
Course breakdown and historical weather.
The world's premier short-course series comes to London
London, United Kingdom · July 26, 2026
The London T100 Triathlon brings the Professional Triathletes Organisation's premier racing format to the British capital. A unique format covering approximately 100 km total distance with a focus on intense, spectator-friendly racing. Set in one of the world's greatest cities, this event combines elite competition with accessible amateur racing.
- Swim
- 2.1 km
- Lake
- Bike
- 80.7 km
- ↑334m · Flat
- Run
- 18.1 km
- Flat
- Air Temp
- 13–27°C
- Water Temp
- 19°C
- Wind
- 6 km/h
- S
Swim Course
London swim — city centre racing
The swim takes place in a central London venue. The T100 format features a shorter, faster swim than traditional IRONMAN distances, emphasising speed and transition efficiency. London's urban water venues provide a unique backdrop for triathlon swimming.
- Central London setting
- T100 format — shorter, more intense swim
- City-centre spectator access
- Unique urban swim experience
Bike Course
Racing through the streets of London
The bike course navigates London's streets. The T100 format emphasises technical, spectator-friendly circuits rather than long point-to-point courses. Racing through one of the world's greatest cities creates an electrifying atmosphere. The urban setting means flat terrain with tight corners rather than open road climbing.
- Racing through iconic London streets
- Spectator-friendly circuit format
- Flat urban terrain with technical corners
- World-class city backdrop
Run Course
Run through London's landmarks
The run takes athletes past London's iconic landmarks. The T100 format delivers a fast, concentrated running experience with strong crowd support throughout. Running in central London with the city's architecture and energy surrounding you is a unique triathlon experience.
- London landmarks as the backdrop
- Concentrated spectator support
- Flat urban running
- T100 format — intense and fast
Race Day Conditions
British summer — mild and unpredictable as always
Late July in London offers warm summer conditions by British standards. Air temperatures range from 16–26°C with the ever-present possibility of showers. London summers can deliver pleasant warmth or grey skies — prepare for both.
Plan London T100 Triathlon 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.