The Average Water Temperature of Every IRONMAN Triathlon in the World

Presenting the average water temperature for every IRONMAN, 70.3, and 5150 race, so you can figure out what to expect—and what swim gear you need—at your next event.

Want to dive in right now? Jump to the spreadsheet. Or download the CSV file so to sort by event, location, date, temperature, and body of water (lake, ocean, etc.).

A few fun facts

Two of the top 3 coldest swims are in California.
IRONMAN 70.3 Oceanside (57°F / 14°C) and IRONMAN 70.3 La Quinta (58°F / 14°C). IRONMAN Valdivia in Chile ties Oceanside for coldest swim.

Events in Cartanega, Colombia, have the warmest swims.
5150 Cartanega in September (86°F / 30°C) and IRONMAN 70.3 Cartanega in November (85°F / 29°C).

The average water temperature of all IRONMAN events is about 71°F / 22°C.

Read on for important info about IRONMAN wetsuit rules, and what to pack for your next race so you show up ready to rock the swim.

FIRST, THE RULES: IRONMAN WETSUIT RULES & TEMPERATURE CUTOFFS

• Wetsuits are legal in water temperatures up to and including 76.1°F / 24.5°C.
• Wetsuits are prohibited in water temperatures above 83.8°F / 28.8°C.
• Wetsuits are mandatory in water temperatures below 60.8°F / 16°C.
• Neoprene caps are legal whenever wetsuits are legal.
• Booties are legal ONLY in water 65°F / 18.3°C or colder. 

WHAT TO PACK FOR YOUR IRONMAN, IRONMAN 70.3, and 5150 SWIM

For races with average temperatures:

• 84°F / 29°C and above: pack a swimskin 
• 70-82°F / 21-29°C: pack a swimskin and a wetsuit
• 69°F / 20.5°C and below: pack a wetsuit

And don't forget goggles!

Why such a big range for packing a swimskin and wetsuit? A cautionary tale:

In 2025, a ROKA team member traveled to race 140.6 miles at an event that has traditionally been wetsuit legal. She brought only a wetsuit. On race day, the announcement came that the swim would not be wetsuit legal. She swam in a bikini she'd brought for vacationing.

Was the swim still gorgeous and fun? Yes. Was she way slower—by several minutes—without a swimskin? Also yes. Could she have saved some gas for the bike and run with a swimskin? Yes again. Learn from her mistake. Come prepared for variations on these historic average water temps. 

And now...

AVERAGE WATER TEMPERATURES FOR EVERY IRONMAN EVENT