If you have an above ground pool with the pool filter system and plumbing above ground (like nearly all above ground pools), pipes and pumps can freeze up in less than an hour of minus 32 degrees. The same is true for inground pool equipment that is not running when temperatures are below freezing.
Helpful tips to keep your pool and its equipment safe during freezing temperatures. Run your pool pump continuously when temperatures are near or below freezing. You don't need to run your heater, moving water likely will not freeze.
KEEP YOUR POOL MAINTENANCE UP TO DATE
If you do not keep up with these maintenance items, then the flow of water through your pool equipment will be greatly diminished. In a freeze situation, this can lead to freeze damage on your equipment.
Bring the pump housing into an area where the temperature is above freezing. Eventually, the ice in the pump melts and the pump can be flushed, winterized and reconnected back into the filtration lines of the pool.
Even if you have your pool covered, some debris may still get in it during the winter. For this reason, you should consider running your pump on occasion whenever the outdoor temperature is between 35 and 65 degrees. Around four to six hours should be sufficient to remove debris and help promote good circulation.
Water, like all types of matter, freezes at a specific temperature. The freezing point for water is 0 degrees Celsius (32 degrees Fahrenheit). When the temperature of water falls to 0 degrees Celsius and below, it begins to change to ice.
Water can be frozen at 32 degrees Fahrenheit, 0 degrees Celsius, and 273.15 Kelvin.
The smaller streaks are from condensate coming off falling water droplets — not water that has frozen midair. The air is not quite cold enough to freeze water immediately, which happens at about minus-42 degrees, Terry said.
You might not even be able to freeze it at 32 degrees, but most likely it will be solid after around 10 hours for water equivalent to a normal bottle.
We've all been taught that water freezes at 32 degrees Fahrenheit, 0 degrees Celsius, 273.15 Kelvin. That's not always the case, though. Scientists have found liquid water as cold as -40 degrees F in clouds and even cooled water down to -42 degrees F in the lab.
Freezing happens when the molecules of a liquid get so cold that they slow down enough to hook onto each other, forming a solid crystal. For pure water, this happens at 32 degrees Fahrenheit, and unlike most other solids, ice expands and is actually less dense than water. That is why ice cubes float!
“Contrary to popular perception, pure liquid water does not usually freeze at its melting point, 0°C, and can instead supercool to temperatures as low as -38°C.
So, there is nothing magical about frost forming. 32 degrees is still the freezing mark.
Mild climate pools often freeze across the surface overnight. However, if the ice sheet becomes thicker than ¼” to ½”, it will put pressure on your pool tile and skimmers as the ice expands. Most pool tile is frost-free, but you should keep the water under the perimeter pool tile band to be safe.
Freeze Protection Units allow pool and spa owners to set a desired temperature where their pump and heater will automatically turn on. Once the climate drops to the specified temperature, the Freeze Protection Unit kicks in. It turns on your pump and heater to keep the water moving, which prevents freeze expansion.
Run Filter Pump
An effective way to keep a pool's pipes from freezing or cracking in the cold is to run the filter pump 24 hours a day or set your pump to turn on automatically when temperature reaches a temperature. It will keep the pools water circulating. Doing this maintains a constant water temperature.
And water freezes at 32 degrees Fahrenheit. But it can actually get colder than that, all the way toward what we call absolute zero. This value is equivalent to about -459 degrees Fahrenheit. This is when the water molecules are basically not moving.
Water will not freeze with the temperature air at or above 33 degrees, regardless of how far the wind chill is below freezing. Wind chill has no effect on inanimate objects, and they cannot be cooled below the ambient air temperature.
Frost, ice formed when water vapor on a surface surface is at or below 32°F (0°C) Meanwhile the surrounding air temperature could be above 32 degrees. Our temperature readings are usually measured from five to ten feet above the ground since this is the level we live in.
While the rule of thumb is that water freezes at 32 degrees Fahrenheit (0 degrees Celsius), water can actually stay liquid over a range of chilly temperatures under certain conditions.
The map above shows the position of 33 degrees at various times overnight. I picked 33 degrees because that usually starts decent melting. The 33 degree line will gradually move north overnight. Anywhere south of the 33 degree line should be in the mid 30s at coldest, and should have quick melting of ice.
Chemists have discovered just how cold water can get before it must freeze. How low can you go? For water, the answer is -55 degrees Fahrenheit (-48 degrees C; 225 Kelvin). University of Utah researchers found that is the lowest temperature liquid water can reach before it becomes ice.
The Birth of Ice
The computers helped Molinero and Moore determine how cold water can get before it reaches its theoretical maximum crystallization rate and must freeze. The answer: minus 48 C (minus 55 F).
As a result, you can cool very pure water well below zero degrees Celsius without it freezing. Water in this condition is called "supercooled". At standard pressure, pure water can be supercooled to as low as about -40 degrees Celsius. Supercooled water is kept from freezing only by the lack of nucleation centers.