Why Does the Pool Water Feel Cooler in the Colder Months? - The Aqua Life


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Why Does the Pool Water Feel Cooler in the Colder Months?

Written By

by Eduardo Montes

Published on

November 24, 2022

Thanksgiving has passed. The Halloween candy haul is well in reserve. We’ve gone back in time an hour. The thermometer is beginning to dip regularly, while frost has begun to blanket our mornings. Clearly these are telltale signs of the next winter arriving. A lesser-known sign of the incoming change of seasons, but also still very noticeable, is the coolness of your pool water! If you’ve been noticing that your trips to your swimming lessons are feeling colder and colder, then you have been noticing how the transition from Summer to Winter affects our experiences of the things we do!

Did you notice that the pool feels colder than it used to feel?


Well, there is more than one thing at play here when it comes to why this is the case. First and foremost, we the people in the water, are very right about how the water feels. We are also, for the most part, incorrect about why we feel that way. Our first instinct is to say: “Oh the water temperature has cooled down!” “Wow this room is really warm, but the water feels very cold! Is the heater broken?” “The air in here feels colder than usual? Is there a draft or something?”

To be frank, 9 times out of 10, the water and air temperature are going to register pretty similarly to what we’ve come accustomed to in those Summer months, with only a few slight variations. A pool operator’s job is to make sure that the water quality is up to a safe minimum standard, which usually means a stable pool temperature and chemical delivery system, to keep all readings as safe and as enjoyable as possible for all patrons. This will also include air quality control, but that is usually just a thermostat away for those who are on the sidelines during lessons. Besides, you can layer up, or down while waiting for lessons to end. Those in the water are getting the real feel of the adjustment to the new temperate season.

Then what explains this colder feel?


9 to 5 science compares air and water of the same temperature, to give us the following solutions (and a few others if you are curious to see them):

Water has a much higher Specific Heat Capacity than air, making it a far better coolant than air.

Water absorbs heat —like the coolant in your car engine— meaning it can take the thermal heat energy our bodies give off, while still staying at a very similar temperature. The air around us is not taking heat away at the same rate, unless the air is moving. That’s why fans work!

More intimate contact between water and skin, compared to air and skin, results in a higher Heat Transfer Coefficient which makes water again a better coolant.

When you enter the water, you can consider it like a vacuum packed package. The water is going to envelop every surface of skin available. Being able to take heat away from EVERY section of your body. Air on the other hand, can get trapped under your clothes, and warm you up through the heat transfer. See wool sweaters. The water does not really trap. It likes to stay connected to wherever all the water is, and will adjust its shape to stay intact as much as possible, once again, reaching your whole body, and transferring the heat we radiate.

In the case of fairly thin layers of water evaporative cooling also takes place in the case of water on skin. As Latent Heat of Vaporisation is carried off the water will cool down and eventually skin will cool too due to heat transfer.

So then when you get out of the water, you still have this thin layer of water all over your body. Well, our bodies are giving off heat at all times, and so that layer of water upon exiting, can be compared to sweat on a hot day. The water is going to evaporate into the air, taking some of the heat from your body, cooling you down. The body does not differentiate between sweat and water, and is going to cool off regardless.

Science Focus gives us this great explanation:

Water has a very high volumetric heat capacity. Raising the temperature of a cubic centimetre of water by 1°C takes more than 3200 times as much energy than you’d need to heat the same volume of air by the same amount. This means that the layer of water surrounding your body heats up only very slowly, the temperature gradient between the water and you stays very steep, so the rate of heat loss remains high.

Worse, because water is very dense, even a slight current will penetrate through clothes and between the hairs on your skin. This displaces the water you have already warmed up. On the other hand, air is easier to trap in a stationary boundary layer that can be warmed up and this acts to reduce the steepness of the temperature gradient. Neoprene wetsuits keep you warmer in water because their pores are fine enough to hold the layer of water next to your skin fairly still.

That is amazing, and a little annoying, for those of us trying to better ourselves and prepare for the summer months with some extra swim practices.

What can we do to help with this occurrence?


Well, at least, with this understanding, we can prepare a little, and try a few of the following tips to help us get ready for those sudden temperature difference feelings:

  1. Come to the pool a little early, and get acclimated in your swimsuit – getting your body used to the air temperature will make the shock of getting into the water a little more bearable, than if you just removed your winter garments and jumped right in. Giving your body some extra time to adjust to the new temperature will help with the feel of the water once the lesson starts.
  2. Wear a swim shirt or swimsuit that covers more surface area on your skin – Things like rash-guards, surfing attire, wetsuits, are viable options to help retain body heat while taking swim instruction! (link to where to get some rash guards?) We also have a few wetsuit like garments at some of our locations, so if you have a swimmer who is shivering before getting into the water, tell your instructor, and we will provide your swimmer with something that might help the cold.
  3. Take a lukewarm, cooler shower, before swimming (any shower may do) – Even taking a warm shower will prime your body for the water before your lesson. But if you find the water feels much colder than you are used to, try a not so hot/warm shower before your lesson.! At the very least, it wakes you up. But if you haven’t ever been to a spa day, you are going to get a similar effect and benefit from the cold shower and then hopping into a warmer body of water. It is probably the best trick in the book. Except for you have to kind of enjoy a cool shower. Maybe an oxymoron. But very much an enjoyable practice if you get used to it!
  4. Bring a big dry towel…or two – Kind of obvious, but it also helps! Have a dry towel, and an extra dry towel! Remove as much moisture as possible! It is the water that is absorbing the heat from us, so getting as much of it off after our lessons is going to help with the warming up process!
  5. Dry off well, with layers ready – Winter means good socks, thermal underwear, long-sleeves, sweaters, good boots, an excellent toque, and a scarf around the neck. Capture the heat being emitted from the body, and trap it in the layers of garments prepared for the end of lessons.
  6. Warm Beverage – Water first for after the swim workout. But once you’re about to head outdoors, maybe a warm tea, or hot chocolate out door might be a nice segway into the outdoors!

The temperature is changing! (Not in the pools, but sure does it feel like it), and we are coming around to another season of covid, cold, & flu. And while the change in temperature is not what gets us sick, the fluctuation does make adjustments to your immune system that may give viruses & bacteria an extra edge to combat our bodies. We have to do our best to do the same, by maintaining a healthy, active lifestyle, and also, taking care of how to keep our bodies nice and warm at those temperatures most suitable for our everyday being.

Yes, the water does feel colder. That means, we should take some extra precautions to make sure that the extra chill does not get into the way of the aquatic goals we are trying to achieve.

Remember to ask your instructor for a wetsuit if you feel your child needs one, and we may be able to provide one for you!

If you have any questions, suggestions, or are trying to find the way to taking your first dip into the wide world of water, then reach out to support@theaqualife.ca,and jump in with us at The Aqua Life Swim Academy!