A hot tub uses heated water and jets for hydrotherapy, providing relaxation and muscle relief. The common perception that spas must always be kept at high temperatures, usually 100°F to 104°F, is a misconception. It is possible to use a hot tub throughout the warmer months, transforming it from a source of heat into a refreshing, cool retreat.
Cooling Your Hot Tub for Summer Comfort
Adjusting the water temperature is the first step toward enjoying your spa in warm weather. Most modern hot tubs allow the user to set the thermostat far below typical high-temperature settings. By simply turning the heater off or setting the temperature to its lowest limit, the tub can become a “cool soak” instead of a traditional hot tub.
A refreshing environment is created when the water is set between 85°F and 95°F. This range provides a therapeutic experience without excessively raising the body’s core temperature in warm ambient air. For a cold plunge effect, the heater can be fully deactivated, allowing the water temperature to drop to the ambient outdoor temperature.
Some advanced models are equipped with heat pumps that function as chillers, actively cooling the water. For tubs without a built-in chiller, running the circulation jets without the heater can promote evaporative cooling, which helps lower the water temperature, especially during a soak. Timing your use for cooler evening hours or ensuring the spa is shaded during the day also contributes to a more comfortable summer soak.
Essential Summer Water Maintenance
Warm water conditions significantly accelerate bacterial growth, making diligent water maintenance necessary during the summer. Heat encourages chemical reactions to occur more rapidly, leading to the faster depletion of sanitizers like chlorine or bromine. Water testing should happen more frequently, ideally two to three times per week, rather than the standard weekly check.
The heat affects the stability of the water’s chemistry, requiring closer monitoring of pH and alkalinity. Maintaining the pH slightly lower, in the 7.2 to 7.4 range, helps ensure the sanitizer remains effective. Alkalinity, which acts as a buffer against rapid pH swings, should be kept stable, typically between 80 and 120 parts per million.
Sanitizer levels must be maintained at the higher end of the recommended range (3 to 5 ppm for chlorine or 4 to 6 ppm for bromine) to combat increased microbial activity. Higher summer temperatures and increased usage necessitate more frequent cleaning of the filters. Increased evaporation requires regular topping off of the water to keep the level above the skimmer and prevent pump damage.
Energy Use Considerations in Warm Weather
Running a hot tub in the summer results in lower energy consumption compared to winter months. This reduction occurs because the heater, the unit’s most energy-intensive component, operates far less frequently or not at all. The heater does not need to compensate for the large temperature difference between the water and the cold outdoor air.
While the circulation pump still runs to filter and maintain water quality, the overall energy draw is minimized because the primary heating demand is gone. Using a well-fitted, insulated cover remains important, even when the heater is off. The cover prevents solar heating from pushing the water temperature too high and reduces water loss from evaporation, saving on water and chemical replacement costs.