I have an small inground pool in the backyard. I live in central Florida, so it doesn't get too cold around here very often. However, tonight there is supposed to be a hard freeze (24°F for 4-7 hours) and I'm a little worried about the pool.

If I do nothing in particular, might that be bad for the pool? If so, what can I do to protect it?

Edit: The pool still has all its water in it and isn't covered. We don't tend to empty pools around here, and I don't own a cover.

  • Are you sure it is going to be -24°F? Or did you mean it is dropping below freesing to 24°F? EDIT: It actually looks like maybe you are using the hyphens to make a parenthetical statement. It would be less confusing it you just use parentheses instead.
    – auujay
    Dec 14, 2010 at 18:51
  • neg 24F would be national news, and an all time record. Run the pumps for a couple of hours and relax Dec 17, 2010 at 0:18

7 Answers 7


I honestly doubt that it will freeze over in that time, as the water will take some time to get anywhere near freezing temps.

If you are worried anyway, a good idea is to leave the filter pump running. Water that is still will more easily freeze over.

Of course, if you were truly worried, you could make it into a salt water pool, dropping the freezing temperature by a few degrees more.

  • 11
    I'd agree, and it's especially important to keep the pump on because it's the water in the pump and pipes that will freeze first, which will crack the pipes and/or pump/filter parts.
    – gregmac
    Dec 14, 2010 at 2:19
  • 1
    gregmac makes an excellent point. The surface of a pool freezing will not harm anything, but a frozen pipe or pump will be a problem.
    – user558
    Dec 14, 2010 at 11:53

At +24 deg F, just run the pumps, and you'll be fine.

The temperature of the pool is often significantly above the temperature of a winter night's air. It takes a long time (or a massive amount of energy) to change the temperature of a pool significantly, and even if it gets cold during the night, the pool will also heat up a little during the day. As long as you keep that above-freezing water going through the pump, it will be fine.

On top of the fact that the pool's water is above-freezing, running the pump moves the water, and moving water is much, much harder to freeze than stagnant water.


We don't empty pools in a Florida. They are used almost year round, especially if you have solar heat. But, you should definitely run the pump overnight to prevent the water in the pipes from freezing and causing damage.


Don't EVER empty your pool in FL. You could float it. Meaning, the water level in the ground is very high. Without the water in the pool holding it down, emptying it can literally pop the whole thing out of the ground. This usually happens during hurricanes/tropical storms. People do crazy things to prep, and empty their pool. As ground becomes increasingly saturated with storm rain-out pops the pool.


We live in Washington state and our temps fall below freezing quite a bit. We put a log in the swimming pool. That prevents the ice from expanding and affecting the pool walls.

  • 1
    Please explain what is meant by "a log". Water expands as it freezes regardless, and an object in the pool may provide a point at which the ice can crumple to prevent extreme pressure on the pool walls.
    – isherwood
    Jan 6, 2016 at 15:52
  • Just noticed this request for more info. the log or pealing pole helps keep the water from becoming a solid sheet of ice, in the Pacific north west it gets cold enough to freeze pools mine is about 2" thick right now. I have several that I paint black the sun keeps them warm so the tiles are not broken like when the entire surface freezes. Here small logs are cheap left overs from plywood processing but they do help. 24 at night probably won't be a problem if the daytime high is in the 50s we run our pump below 26 to protect the pipes
    – Ed Beal
    Dec 18, 2017 at 16:09

NEVER EVER EMPTY ANY POOL OF IT'S WATER!!!! If it's an inground fiberglass pool, it will definitely "float" or pop out of the ground. If it's a vinyl liner inground pool or above ground pool, it will ruin your liner.... Your liner will shrink and then you will be replacing the liner once the weather gets back up to warmer temps. Ideal installation temperatures range between 50° and 80° F. During the times, when the weather is below freezing, you need to do 1 of 2 things: either winterize your pool completely or keep the pump running 24/7.

  • Your ALL CAPS sentence is, as a general statement, wrong. It should read "Never empty a pool of its water if it has not been designed to be emptied". Pools in Florida will not have been so designed; pools alongside the Rhein in Germany and Switzerland (where I live) absolutely are so designed - a pool full of water at -10C will do a lot of damage to the side walls. Nov 8, 2019 at 11:44
  • Hello, and welcome to Home Improvement. @MartinBonnersupportsMonica is right, but aside from that your answer is good; would you edit it? And, you should probably take our tour so you'll know how best to contribute here. Nov 8, 2019 at 12:58

That's cold... Of course it depends on the material the pool is made of, but emptying it should be fine, but I suppose it is empty already.

  • Nope, not empty. I wasn't aware that was normal!
    – Mag Roader
    Dec 14, 2010 at 1:09
  • 3
    Actually it depends on the question. If it is hard freeze -24°F which is -33°C (my scale) you should definitely empty it. But if it is 24°F = -4°C it is barely freezing and one night will not do anything to your pool.
    – Lukas
    Dec 14, 2010 at 7:47
  • 4
    @MagRoader Yikes, it's not normal. You do NOT empty in-ground pools in Central Florida unless you are a professional who knows what they are doing. Without the proper relief valves in place, the hydrostatic pressure underneath the pool can actually lift the pool out of the ground, and you'll find it floating across your backyard during the next rainstorm. Don't do that. Jan 7, 2014 at 23:45

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