Ideal Hot Tub Temperature for Summer, Winter, Kids, Pregnancy

Just picture this: It’s been a long, stressful day, and all you want to do is sink into your hot tub and let the warm water work its magic. But as you dip your toes in, you realize that the temperature is all wrong—too hot, too cold, just not quite right.

We’ve all been there and know how frustrating it can be. That’s why we’ve put together this article to help you find the ideal hot tub temperature for a truly relaxing and rejuvenating soak.

But just how hot is a hot tub supposed to be? Should the temperature be changed for summer and winter, or kids, pregnancy or those with health problems?

Of course, the perfect hot tub temperature depends on the user’s age, health condition, season and personal preference.

How Hot Do Hot Tubs Get?

It is generally accepted that the hot tub temperature matters and the maximum hot tub temperature for safety is 104ºF (40ºC). Extending 104 degrees may not be safe, particularly for some groups of users, as reported in Science Direct.

Sitting in hot water raises your body temperature, particularly above body temperature, which is 98.6ºF (37ºC).

Having an excessively high body temperature above 103ºF (39.5ºC) can cause serious heat-related health risks such as:

• Cramps
• Rashes
• Fainting
• Nausea
• Heat exhaustion
• Heat stroke

Because of these risks, most modern hot tubs can’t be set to anything over 104ºF (40ºC). To further prevent these illnesses, you should limit your time in a hot tub to 15-30 minutes per session.

Finding the ideal temperature for hot tub water is a matter of personal taste and often requires a compromise. For example, I find a good hot tub temperature to be around 102ºF but my wife finds that too hot so she prefers it around 98ºF. So we meet in the middle and have it at 100ºF.

Best hot tub temperature

Hot tub temperature in winter

Most hot tub owners would agree that increasing the hot tub temperature a degree or two makes it much more inviting in the winter months. This is particularly true in a cold part of the country.

Going from a cold air temperature into water that is 102ºF and then getting back out can be invigorating – rather like going from a sauna into a cold plunge pool and then back into the sauna again. Scandinavians have considered the rapid temperature changes beneficial for years.

Of course, if you live in a warmer climate or have an indoor hot tub, the temperature difference will not apply.

Hot tub temperature in summer

That hot, steamy water feels so good in cold weather, but what should you do on warm summer days?

Many hot tub users love to cool off in their hot tubs during the hottest months of the year. Setting the hot tub’s heater to around 80ºF (26.5ºC) to 85ºF (29.5ºC) will offer a refreshing and relaxing summer soak, without the water feeling too cold. Plus, you can stay in the water for a much longer time!

Is there a minimum temperature for a hot tub in summer? Some manufacturers will only allow the minimum temperature for a hot tub to be set to 80ºF (26.5ºC).

To keep the water cooler in your hot tub, try these tips:

• Prop the cover slightly open to prevent heat from building up, while still keeping the water covered.
• Run the jets to circulate the water and cool it down
• Clean filters frequently (once or twice weekly) to maintain good water circulation.

You can also add ice! It’s a fun party trick, and it will keep your tub’s temperature cooler.

Hot tub temp for kids

Children are less tolerant of extreme temperatures than adults are. Kids aged 5 and up will be safer and much more comfortable in water no higher than 98ºF (36.5ºC). 

Kids should never soak for more than 15 minutes at a time, and children under 5 should not go in hot tubs at all. Webmd says that babies’ thin skin makes them more susceptible to overheating.

It should go without saying that children should always be constantly supervised by an adult when using hot tubs. Ideally, the cover should be locked when it is not in use to prevent children from getting in without supervision.

Hot tub temperature when pregnant

A safe hot tub temperature for pregnancy is not as high as normal.

When a pregnant woman’s body temperature rises above 102.2ºF (39ºC), the baby’s risk of birth defects can increase. This is why it’s also important for expecting mothers to speak with their Obstetrician before entering hot tubs.

Although little research has been done, Healthline advises that “during pregnancy hot tubs should be used cautiously or not at all.”

How hot should a hot tub be when not in use?

If you will not be using your hot tub for several days or more, perhaps when going on vacation, then you may wish to lower the temperature to save money on electricity.

Normally, you would not lower the hot tub temperature by more than 5 degrees when not in use.

You will have to remember to raise the temperature again in plenty of time before you use it as it will take some time to reach the normal temperature again.

If it will only be a day or two between uses, I would leave the temperature alone, particularly if you have a good cover to retain the heat.

Also read: Do you leave hot tubs on all the time?

Can people with health conditions use hot tubs?

A good soak can help many people with certain health issues, particularly joint or muscular problems.

However, older adults and people with health conditions should consult a physician before using a spa. Even if advised they can use one, they should avoid temperatures that are too high and staying too long in a session.

Those with heart or blood pressure problems must be especially cautious, as sudden immersion in hot tub water is likely to increase their heart rate and blood pressure, which could cause problems. These are the results of a study comparing immersion in a hot tub with exercise.

Best practices for hot tub heaters

Heating a hot tub to the desired temperature can take a few hours, which is why some hot tubs have accompanying smartphone apps.

If you’re away from home, you can set the temperature beforehand so your hot tub is warmed up and ready to go when you are!

How to run a hot tub economically

It may seem counterintuitive, but frequently changing the settings on your hot tub heater does not save you money. Turning it down, then up, or off, then on, actually burns more energy and costs more than leaving it set at one temperature.

Changing temperature settings will also shorten the lifespan of your hot tub’s systems and heating element.

If you use your hot tub regularly (at least a few times each week):

• Keep the heater set at a constant temperature so the water stays warm
• Ensure the top and sides of your hot tub are insulated.

With these tips, your hot tub heating element won’t have to work nearly as hard.

Keeping hot tubs in good condition

Many hot tub users keep a second thermometer, separate from the heater’s gauge, to confirm safe temperatures and ensure the heating element is working correctly. One such thermometer is one of these floating spa thermometers available on Amazon.

Detecting early warning signs of equipment malfunctions can help you prevent worst-case scenarios, like your heating element going out and your pipes freezing if you live in a cold area.

Frequently asked questions