Complete Tri

At what temps can you use a wetsuit?

Wetsuits are common in triathlons, but not always universally allowed. Most triathlons allow wetsuits if the water temperature is going to be below a certain level. The most hard and fast rule about what temperature makes a race wetsuit-legal comes from the USA Triathlon association, which states that swimmers using tri wetsuits at water temps of above 78 degrees are not eligible for official race awards. In addition to the USAT’s stated guideline, the following rules of thumb are common based on many years of observing race directors’ decisions, racers behavior, and published race rules on the open water swim portion of a triathlon.

Not Sanctioned vs. Not Allowed

In some races, especially those on a warm summer day when the water is warm, a Race Director may actually ban wetsuits altogether.  This means that you show up to race, but are told that you can’t use the wetsuit.  This is almost always due to safety reasons, and the race team wants to be sure that they don’t have swimmers overheating in the water.  The other option is that the wetsuits are allowed but not sanctioned, meaning that anyone racing with a wetsuit is not allowed to place or win an award.  You can still do the race, with your timing chip and the full support of race volunteers.  You just can’t be up on the podium after the race with an award.

USAT’s Official Wetsuit Rule

The USAT is the governing body of triathlon in the United States, and typically calls the shots for rules such as wetsuit legality, drafting on the cycling, and equipment specifications.  For 95% of racers, the goal is simply to follow the rules enough to be able to safely race.  However, to those looking for an elite, podium-style finish, knowing these rules is pretty critical.  Here are the USAT’s rule on wetsuits and water temps.

(all temps refer to surface water temperatures)

Under 50 degrees: Not suitable for open water swimming, even with a wetsuit
50 to 65 degrees: Suitable for open water swim, but wetsuit is highly advised
65-78 degrees: Suitable for swimming with or without a wetsuit. Sleeveless suits are popular at this temp.
78-84 degrees: Race directors use their judgement to allow or not allow wetsuits at this range
Over 84 degrees: Wetsuits not allowed


The range of 50 to 78 degrees is therefore the ideal range for using a wetsuit. Any warmer, and the swimmer may actually overheat due to the wetsuit’s insulative qualities.  Truth be told, we think it is pretty easy to get too warm inside a wetsuit even in the 74-77 degree range.  Any colder that 50, and the water is dangerously frigid for a swim. Keep in mind that even with a full-length wetsuit, you have a layer of water against your skin (that warms up gradually) and that your head, forehead, and neck are still exposed to the cold water. It is very common to have an otherwise comfortable swim where your forehead is so cold it makes for an uncomfortable swim.

Just for some perspective, in our opinion, water (without a wetsuit) feels quite cold under 65 degrees.  Comfortable around 70-75.  Too warm as you approach 80.

Of course, it is not just about the rules. The wetsuit answer might be different for every individual.  Here are a few factors that you should weigh, in addition to the race director’s rule, regarding using a wetsuit:

Swim Ability:  This one is pretty obvious, but if you are a weaker swimmer you may want to use a wetsuit if it is allowed, no matter what.  Wetsuits help your buoyancy, and that can help your swim performance both physically and psychologically in addition to adding an element of safety.  Having an open water swim “panic” is very common, and you are more likely to work through it if you know that the wetsuit is giving you some extra lift.

Wetsuits can be very helpful during a race, but they take a minute to put on and take off so many not make sense in very short races.

Conditions:  Swimming on a windy day or in salt water can introduce unpredictable variables.  When in doubt, you may want to use a wetsuit if the day’s conditions create factors that you don’t feel as comfortable in.  A wetsuit can not only keep you warm, but basically create a safety blanket that could be a welcomed addition when conditions have you nervous about the swim leg.

Your Training:  “Nothing new on race day” is a common matra of seasoned racers.  Race day is not the time to test a new approach or technique.  If you have only trained in wetsuits when in open water, use one on race day.  If you have never tried a wetsuit, you may want to forego one for the race (unless that is also your first open water swim as well — in which case, shame on you for not practicing in open water sooner).  By the way, the same goes for your other swim gear — use the same swim goggles as you do in your practices, and make sure you have tested whatever you plan to wear under the wetsuit.

Distance:  With the advent of many shorter races, modified sprints, the swim distance can sometimes be so short that any time you save in the water by wearing a wetsuit can easily be lost in the transition.  Taking a wetsuit off in T1 can easily take 60 seconds alone.  If the swim is only 1/4 or 1/3 of a mile, you might be better off, timewise, by not having to contend with the suit during that first transition.  You can shave a good minute off of your transition time if you decide to swim without a wetsuit.

If you are new to the sport of triathlon, be sure to check out our other swim-related articles on how to use a wetsuit for newbies, and what to look for in the right entry-level wetsuit.