The procedure involves preparing an above ground swimming pool for the off-season, typically during the colder months, to protect it from damage caused by freezing temperatures and to simplify the reopening process in the spring. For example, this preparation can include draining some of the water, adding winterizing chemicals, and covering the pool.
Properly preparing a pool for winter offers multiple advantages. It prevents pipes from bursting due to freezing water, minimizes algae growth, protects the pool liner from damage, and reduces the amount of cleaning and maintenance required when the weather warms. Historically, variations of this preparation have been employed for any water system prone to freezing, although specific methods for swimming pools are a more recent development.