Ah, the hot tub, a haven of bubbling bliss, where muscle knots melt away and stress evaporates, but amidst the relaxation, a crucial question emerges: what’s the safest hot tub temperature? Too hot, and you risk overheating, too cold, and the magic dissipates. For centuries people have soaked in hot water to help them relax, relieve pain, and de-stress. Hot tub temperatures range from 90-104°F depending on factors like the location of your tub, the climate and weather, and your age and overall health. Let’s dive into the science of heat and explore the sweet spot for ultimate safety and spa-level delight.

How Hot is the Average Hot Tub?

The U.S. Consumer Product Safety Commission (CPSC) advises to never exceed 104°F (40°C) in your hot tub. Going beyond this temperature risks heat stroke, a potentially life-threatening condition with symptoms like dizziness, nausea, and even loss of consciousness. While 104°F is the upper limit, the majority of hot tub users prefer a water temperature between 100°F-102°F (37.5-39°C), and some prefer the water to be a little cooler and closer to body temperature around 98°F. 

The ideal temperature is a personal choice. Here are some guidelines for you to get started. 

• 100-102°F (37.8-38.9°C): This sweet spot is perfect for most healthy adults, promoting relaxation while minimizing overheating risks. It’s like a gentle hug from warm water, easing tension and soothing muscles.
• 98-100°F (36.7-37.8°C): Prefer a cooler soak? This lower range is ideal for pregnant women, children, and anyone sensitive to heat. It’s like a refreshing dip in a tropical lagoon, invigorating and calm in equal measure.

It’s best to start low and gradually raise your water temperature until you find what’s comfortable for you. Also consider the age and health of others that may be joining you and set a temp that will be appropriate for everyone. If children are present the recommended temperature is around 95°F or less so they don’t overheat. Women who are pregnant shouldn’t exceed 101°F and like children should also limit the time of their soak. 

It’s also common for hot tub owners to change the water temperature depending on the time of the year. Many spa owners like to increase the temperature during cold winter months, and conversely if you live in an extra hot climate or during the summer months, you may consider dropping the temperature. Keeping your water temperature below 98°F can be refreshing while still providing the warm water that makes you feel so relaxed.

How Long Does it Take a Hot Tub to Heat Up?

After filling your spa for the first time, you should allow 18 to 24 hours for your water to reach a temperature of 100°F (38°C) depending on the size of your tub. Generally speaking, water heats up around 5-10°F per hour. Otherwise depending on your set up, starting temp and thermostat level, it can take anywhere from 3-8 hours to heat up your tub. Whether you leave your hot tub running all the time is a personal choice, and that will also affect how long it takes to heat it up.

Leaving your hot tub running all the time will give you a head start on reaching 100-102° but may cost you more on your electricity bill. If you live in a milder climate or use your spa infrequently, you may choose to shut it down or turn the temperature way down until you want to use it again, which means it’ll take longer to reach the desired temp. Your tub will heat faster if the water inside starts out warm or if the air around the tub is warm.

If possible, keep your hot tub in a sunny spot to take full advantage of the sun’s warmth. You can also influence the environment around your tub by blocking out wind by installing a fence, setting up a windscreen, planting shrubs or enclosing your tub in a small gazebo. Using a cover is probably the easiest strategy to keep heat in and water from evaporating and also to keep debris out. 

If you have any questions or concerns about your water temperature or tub, drop us a line! We can help you find the perfect hot tub and give you advice on how to make the best of your new relaxation oasis.