Triathlon water temperature: where the swim is cold, and where it is warm

Each race has one figure: its average water temperature, drawn from previous editions. The temperature on race morning can sit a few degrees either side, and the wetsuit decision is taken then.

This page uses those averages to show where and when the water is cold or warm. The water temperature guide goes through them race by race.

Grouped by region, the averages spread widely, and the ordering follows latitude and ocean currents:

• Europe: median 19 °C across 82 races
• Oceania: median 21 °C across 21 races
• Africa: median 21 °C across 6 races
• North America: median 22 °C across 52 races
• Latin America: median 23 °C across 31 races
• Middle East: median 23 °C across 7 races
• Asia: median 25 °C across 26 races

Grouped by month instead, the medians stay within a few degrees of each other all year, because the calendar follows the seasons: races are scheduled when the local water is at a workable temperature.

The IRONMAN calendar follows the same question month by month for full-distance IRONMAN races.

At the cold end, 58 races have an average of 18 °C or less. A wetsuit is close to universal there where it is allowed, and a swim shortened for conditions is a real possibility.

At the warm end, 56 races average 24 °C or more. Above roughly that point wetsuit use is commonly restricted, and swim comfort becomes a question of heat. The exact threshold depends on the rules applied to each race.