What is an ideal swimming pool temperature? This is a difficult question to answer because it varies based on individual swimmers preferences. Based on recommended heater temperatures and settings from virtually all manufactures, the ideal range for both indoor swimming pools and outdoor swimming pools is anywhere from 75 degrees to 85 degrees Fahrenheit. This figure should not be thought of as final as temperature and comfort does differ from person to person and environment to environment, but it a good goal to reach.

If you have a backyard swimming pool without a heater, looking for an ideal temperature is a difficult task. The temperature of the swimming pool will gradually increase as the season changes and as the pool heats up, but the initial temperature of your swimming pool in the early parts of the swimming season will be quite cold – usually well less than 70 degrees Fahrenheit. Even though there is no proper pool temperature, swimming pools less than 65 degrees Fahrenheit are unpleasant even for the most adventurous swimmers. On the other side, if you do have an outdoor swimming pool with a heater, set it at something that is comfortable to your swimmers and your activity level. For instance, cooler pool water is more ideal for exercising where warmer water is better for a lounge / beach atmosphere. But, keep in mind that turning up your heater too much can lead to unexpected drama.

When you increase the temperature of your swimming pool water, it can have an effect on pool maintenance. With higher temperature comes more water evaporation. This means you will need to be more diligent about filling up your swimming pool to keep the water in your skimmers. Higher water temperatures also mean a faster buildup of dissolved solids. This is basically the "bad stuff" that the chlorine attacks in swimming pool water. Higher pool water temperatures will also burn off your chlorine and pool sanitizing agents much more quickly. Algae also love the hot water so they will grow faster and force more serious and diligent swimming pool vacuuming, squeeging, and cleanup.

Even if you don’t have a swimming pool heater to maintain your swimming pools temperature, the same concerns of a warmer pool will eventually plague your pool in peak summer heat environments. Keep an eye out for seasonal changes and how they will affect your water chemistry. The most important reading in your swimming pool during hot and cold times will be your total alkalinity. When the weather is cooler, your total alkalinity should be increased. In warmer weather, your total alkalinity should be decreased with a muriatic acid to keep the saturation index fairly constant.

There is no ideal swimming pool temperature but you should adjust your temperature based on your individual preference. Also, keep in mind the added responsibilities that come with maintaining a warmer pool. Watch out for seasonal changes and note how they affect your swimming pool chemistry. Both cold and warm temperatures have an effect on pool chemistry and maintenance routines.