Outdoor Pool Temperature vs. Air Temperature: What Is Ideal?

Outdoor Pool Temperature vs Air Temperature

If you’ve ever splashed around in an outdoor pool, you already know how different the air can feel once you swam. It’s not unusual for people to worry about it being too cold to swim. The area’s air temperature will affect your swimming pool’s temperature and your health. Ever wonder when it is too cold to swim?

Most experts agree that the safest and most comfortable swimming pool temperature rests between 78 to 86 degrees Fahrenheit. If you have a heated pool that is meant to act as a spa zone, it can be as warm as 114 degrees. All pools should have their temperatures regulated carefully for safety’s sake. 

Being new to pool ownership makes things a lot more intense than you might expect. Here’s what you should know about pool temperatures and how to work with the air temperature around you.

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Why Does Pool Temperature Matter?

Swimming in a pool that’s extremely cold is not pleasant, nor is it something that most people want to experience. People who are sensitive to temperatures could also become at risk of temperature shock or hypothermia. That’s why it’s important to make sure that you have a healthy and safe pool temperature if you want to swim.

What Is A Safe Pool Temperature?

The best temperature for a typical pool rests between 78 to 86 degrees Fahrenheit. This is not only comfortable for swimming, either. It also means that you won’t be freezing or shocked when you leave the pool.

(Note: Just so we’re clear, the term “pool temperature” refers to the temperature of the water. It’s weird that I have to say that, but hey, it’s how things work. )

How Can You Measure The Temperature In Your Pool?

The easiest way to measure the pool temperature is to install a pool thermostat in your pool. (Actually, most pools should have this if you think about it.) This offers you a way to regulate the temperature of your pool. However, there are other ways to tell the temperature:

  • Thermometers. Pool thermometers are great, and can be attached to the side of your pool for a low price. You can choose from a floating pool thermometer, an analog thermometer, or an infrared pool thermometer.
  • Thermostats. I mentioned this before, but I’ll say it again. Your pool thermostat will not only regulate your pool temperature, but will display the temperature it’s currently at.
  • Your Hand. Hold your hand above the water to gauge if it’s cold. Then, dip your hand in the pool for 5 to 10 seconds. Does it feel comfortable? If not, it’s too cold. If the pool temperature is warm but not hot, it’s around 100 degrees.

Can You Keep A Heated Pool Open When The Air Temperature Is Freezing?

Temperature shock can happen with people who are sensitive to cold weather, but on a technicality, it’s safe. It isn’t unusual to see a heated pool being used in winter in areas like Sweden and Norway. Some actually consider this to be a spa treat, but it’s usually just a way to make sure that you keep your pool access year-round.

Though it’s a possibility that many people seem to enjoy, it’s not for everyone. If you are worried about catching a cold from getting out of the heated pool in the snow, it may be better to cover your pool for the season.

How Does Air Temperature Impact Your Swim Quality?

Pools can lose a lot of heat through exposure to open air. In fact, it’s pretty normal for your pool temperature to be roughly the same temperature as the outdoors around you. That’s why most pools only begin to open to the public after May or June. (It needs to be around 80 degrees for the pool to be warm enough without heating.)

Can You Open A Pool For Swimming In Spring?

This all depends on the temperatures where you live. If you don’t have a pool heater, it’s going to be rough. In parts of Florida, California, and Texas, it rarely ever dips below 80 degrees. However, if you’re in New Jersey, you’re lucky if you can keep your pool open in May.

Does A Warmer Pool Cause Safety Issues?

Honestly, it could potentially cause some forms of mold and bacteria to grow faster. That can be fixed with more frequent pool shocks. The truth is that warmer pool temperatures don’t pose the same problems that cold pools do. It’s just a bit icky feeling—like bathwater.

How Much Can Air Temperature Impact Your Pool?

Air temperature can play a huge role in how safe your pool is. In most cases, the water will remain roughly the same temperature as the air around it unless there are preventative measures taken. Heat loss, in particular, is a major issue with colder air temperatures.

How Can You Keep Your Pool Warm?

If you want to get the best experience out of your pool, you need to know how to keep your pool warm. This is going to involve a little legwork, but it’s worth it.

  1. Consider getting a pool cover. Your pool will lose anywhere from 15 to 25 percent more heat if you leave it uncovered overnight. A heat-trapping pool cover will prove to be the most eco-friendly option on this list.
  2. Cut down trees nearby. Along with making leaves and sticks fall in your pool, trees bring shade to the area. Sunlight naturally heats water.
  3. If you can wing it, buy a pool heater. I absolutely understand why so many people are leery about buying pool heaters. They tend to eat up energy pretty quickly and cost a fortune to use. However, they are a good way to guarantee an ideal temperature in your pool time after time.
  4. Use black garbage bags. Spread a black garbage bag over a hula hoop, and throw it in the pool. The blackness of the trash bag will trap heat and send it out through the pool water.
  5. Consider painting your pool bottom black. It’s a bit extreme, but if you live in an area where things are colder than normal, it works. Black pools naturally contain more heat, which in turn, can increase your water temperature naturally.

How Do You Cool Down A Hot Pool?

Hot pools aren’t bad, but they are uncomfortable. They can also feel kind of gross, like taking a bath with a bunch of people. It’s good to know how to cool down a hot pool when the temperatures are a bit too high. Here’s how:

  1. Run your pool filter at night. Pool filters can contribute to water heating. At night, temperatures already dip down below the norm. This makes running your filter at that time a way to minimize the heat your pool retains.
  2. Paint your pool’s bottom white. If you live in an area where high temperatures are the norm, a white pool makes sense. White will reflect the heat back and prevent it from staying in the pool’s water.
  3. Drop ice cubes in the pool. I swear, I know this sounds janky AF, but it works. Ice cubes are frozen. Let them melt in your pool and you’ll get the crisp, clean splash you want. It may take a while for them to melt, so be prepared to see them floating in your pool for a minute.
  4. Keep your pool cover off as much as possible. Evaporation contributes to heat loss. This will encourage evaporation to occur.
  5. Consider getting shade for the area above the pool. A small tent can help prevent the sun from hitting your pool. It’s easier to regulate your pool’s temperature with less direct sunlight hitting your pool.
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Related Questions

How much does it cost to heat a pool year-round?

If you want to run a pool heater year-round, you need to check out the specific type of heater you want. Propane heaters can cost anywhere from $3,000 to $11,000 to heat a pool annually. If you want to go for something more affordable, choose a heat pump. This can keep your pool warm for as little as $700 per year.

When is it smart to have a warm pool?

If you have toddlers or aging family members who are still enjoying a swim, it is better to heat your pool up between 82 to 90 degrees. The warmth of the heat will be easier on their joints and can be soothing for younger children who might panic in a cold pool.

A good rule of thumb is to cater your pool temperature to people who want to swim in the pool. People who are ill or who may want the comfort of a large-scale hot bath should have a heated pool.

How cold are cold plunge pools?

If you have gone to a Russian bath house, you may have noticed that cold plunge pools are freezing cold. They aren’t actually 30 degrees, though, even if they feel that way. A typical cold plunge pool is kept between 50 to 55 degrees Fahrenheit. This is far below a typical pool’s temperature, which is why most people feel like it’s a shock to their system.

Ossiana Tepfenhart

Ossiana Tepfenhart is an expert writer, focusing on interior design and general home tips. Writing is her life, and it's what she does best. Her interests include art and real estate investments.

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