Ideal swimming pool temperature

One of the questions that any heated swimming pool owner will ask themselves is “what is the ideal temperature for the pool water?”

The answer to this question depends upon a number of factors and the other component to consider is the type and output of the heater. E.g. in a cool environment a power source like solar heating will have a limited heat output and this alone may determine the maximum temperature of the water. With boiler powered heaters this is not a problem.

How to work it out

There are many different view points concerning the best and most pleasant temperature for a swimming pool to be maintained at. Who is right and who is wrong is hard to say and personal preference is very important in making this decision.

One good question to ask is this, what is the perceived use of the pool, e.g. is it primarily for sporting activity or relaxation?

One factor that most people agree on is that the temperature of the pool water should be placed in the context of the ambient air temperature and that these two temperatures are related.

One consensus of though is that the ambient air temperature should generally be slightly higher than the temperature of the pool’s water, at least for indoor pools and pools in warm outdoor environments. Pools in hotels and Spa’s often have the temperature of the water in the swimming pool set to be one to two degrees lower than the air temperature in the pool room (but rarely above 30 degrees Centigrade.)

In the case of swimming pools in the Mediterranean or states like Florida (USA), where outside air temperatures regularly exceed 30 degrees Centigrade (and can often get close to 40 degrees centigrade), many owners set the pool water to somewhere just below 30 degrees Centigrade.

One reason for this apparent maximum is that at higher temperatures the quality and hygiene of the pool’s water becomes harder to manage and this is not desirable. The level of water evaporation also becomes significant at these temperatures and again this is undesirable for a number of reasons.

Personal preference

Aside from general guidance, some people like a warmer pool whilst others prefer a cooler one. Trial and error is one good way of finding out what suits you (and your family), but always take into consideration the ambient air temperature.

Most people do not want to feel cold when swimming, however a pool should feel refreshing and invigorating and, if the pool water gets too warm, this will not be the case.

Many small pools are used very much for taking a dip to get out of the hot sun and cool down. With these pools you do not want to be shocked by the coolness of the water, but equally you do not want to feel uncomfortably warm within 5 minutes of getting in. Striking the balance is important.

With larger pools higher levels of activity tends to be more popular and, if this is the case, it is a good idea to keep the water slightly cooler. This prevents fatigues, a feeling that the pool is too warm or even oppressive, and it also saves on heating costs.