When are wetsuits allowed in a triathlon?
A · Advanced · The race and the swim · 1 of 3It depends on the water temperature, the swim length and who is racing. For elite athletes in swims up to 1500 m, wetsuits are forbidden at 20 degrees Celsius and above and compulsory at 15.9 and below. Age-group athletes may wear them in warmer water, up to 22 degrees. Very hot or very cold water shortens or cancels the swim.
How it works
- Elite, under-23, junior and youth, up to 1500 m: forbidden at "20 ºC and above", mandatory at "15.9 ºC and below".
- The same athletes, 1501 m and longer: forbidden at 22 degrees and above.
- Age-group athletes up to the 55 to 59 category, up to 1500 m: forbidden at 22 degrees and above.
- The same athletes, longer swims: forbidden at 24.6 degrees and above.
- Age-group athletes of 60 and over: forbidden at 24.6 degrees and above at all distances.
- Compulsory for everyone: at 15.9 degrees and below.
- In between: the athlete chooses.
- Too hot or too cold: a table shortens or cancels the swim. Above 33 degrees and below 11 degrees it is cancelled at every distance listed.
- Maximum stay: time limits in the water also depend on swim length and category.
- Taking it off: a wetsuit may only be fully removed in a designated area or at the athlete's transition spot.
The glossary has the wetsuit, the open water swim, the transition area, the age group racing entry, the tri suit and the cut off time entry.
Tricky cases
The water is 19 degrees. Can an elite athlete choose to wear a wetsuit?
Yes. Between 16 and 19.9 degrees it is neither forbidden nor mandatory for a swim of up to 1500 m.
The water is 21 degrees in a race with elites and age-groupers. Who may wear one?
The age-group athletes may. For elites it is forbidden from 20 degrees in a swim of up to 1500 m.
The water is 12.5 degrees. Does the race go ahead?
With a shortened swim or none. In the table, a 1500 m swim at that temperature is reduced, and below 11 degrees the swim is cancelled.
Who measures the temperature, and where?
The rules set out a procedure in the section on events, which was not read.
Why the rule exists
A wetsuit keeps a swimmer warm and also makes them float higher and swim faster. So it is required when cold water is a danger, banned when the water is warm enough that it would be only an advantage and a heat risk, and optional between. Age-group athletes are given more latitude because they are in the water longer.
Where it differs
| Where | What changes | Source |
|---|---|---|
| Elites, up to 1500 m | Forbidden from 20 ºC | WT 4.2 |
| Age-group to 55 to 59, up to 1500 m | Forbidden from 22 ºC | WT 4.2 |
| Age-group 60 and over | Forbidden from 24.6 ºC | WT 4.2 |
| Everyone | Mandatory at 15.9 ºC and below | WT 4.2 |
From the rule book
World Triathlon, Competition Rules (2026 edition, amended 29 April 2026), sections 4.2 to 4.4 and 7.1. Checked 14 October 2026. Official document: World Triathlon Competition Rules (PDF).