When Should You Close Your Pool? Suggested Times by State/Climate

Summer is coming to a close, and the sunny weather is starting to cool off. One of the inevitable parts of the fall season for pool owners is closing their pools for the winter. As sad as it is, most pool owners in the USA will have to winterize their pools at some point in the year. That said, the exact time you need to close your pool can vary by a few weeks or even months. 

In this article, I will discuss when you should close your pool, breaking down the suggested time to winterize depending on your state and climate zone.

Main Takeaways

• Winterizing your pool is an important task that should not be taken lightly. If you live in a region with freezing temps, not winterizing can seriously damage an unwinterized pool.
• Pool owners in warmer regions of the USA, such as the southern parts of Florida, Texas, and California, as well as Hawaii, won’t need to close their pools in the winter.
• If you own a pool in Alaska, you may only be able to keep your pool open for a month or two.
• To winterize, you’ll need to clean your pool, unhook your equipment, add winterizing chemicals, and cover your pool with a pool cover.

When Should You Close Your Pool?

You should close your swimming pool when the temperature is consistently below 65 degrees Fahrenheit. This is partly because, well… who really wants to swim when it is colder than this? Also, when the outside temperature is less than 65 degrees, there is less chance of algae growth, so you won’t have to worry as much about an algae infestation after closing down your pool.

The U.S. is a massive country, so not all regions drop below 65 degrees at the same time. Generally, with a few exceptions, the climate of the U.S. gets warmer the further south you live and colder as you travel north. So, pool owners in northern regions will typically close their pools earlier than pool owners in the south.

When Should You Open Your Pool?

Most pool owners open their pool at the beginning of summer, with Memorial Day being the unofficial pool opening time for many Americans. That said, as with pool closing, this largely depends on what area you live in.

Remember when I said algae doesn’t do well in temperatures below 65 degrees? Well, as soon as the air temperature starts poking above 65 degrees, algae will start infiltrating your pool water. So, the best time of year to open your pool is when the temperature goes above the 65-degree mark.

In warmer areas of the country, pool owners may be able to open up as early as mid-March. In contrast, Alaskans may need to wait till mid-July to jump into the water!

Still uncertain of when to open your pool? Check out my article on the best time to open your pool for more!

Best Time to Close the Pool in Different Climates/Regions

As I mentioned above, the exact time of year you close your pool greatly depends on your region and climate. Here is a breakdown of when to close your pool, depending on your specific region.

Northeast

The Northeast is comprised of New England, as well as New York, Pennsylvania, and New Jersey. This region, especially New England, is known for its brutal winters and relatively short summers, so pool owners in the Northeast will usually start closing their pools around the end of September. This gives you enough time to prepare your pools for the cold weather before the first freeze and prevent any unnecessary damage to the pool.

Midwest

The Midwest is another region of the USA that experiences long, biting, cold winters. Illinois, Indiana, Ohio, Michigan, Wisconsin, Minnesota, Iowa, and Missouri are the states making up this climate region of the USA. If you live in the Midwest, you may start winterizing as early as late September or early October. Those in northern states of the midwest, such as Michigan, Wisconsin, and Minnesota, may even close down in early September.

South Florida/South Texas/Southern California/Hawaii

The southern regions of Texas, Florida, and California, as well as Hawaii, are the warmest parts of the USA that tend to have extremely hot summers and mild winters. In these regions, closing pools for the winter is less common. These regions may not consistently drop below 65 degrees, so you won’t be able to winterize properly. In fact, in Hawaii, it rarely gets lower than 80 degrees during the day, so you can continue enjoying your pool all year!

Southeast

The Southeast is a relatively warm region of the USA that also experiences relatively mild winters. While you may not be able to keep your pool up and running all year in these states, you’ll get a much longer pool season here than in northern states. The Southeast comprises Virginia, North and South Carolina, Georgia, Alabama, Mississippi, Louisiana, Florida, and Tennessee. If you are a pool owner in the Southeast, you won’t have to close your pool until mid to late October. In some cases, in warmer areas of the Southeast, you can wait until early November – especially if you have a pool heater!

Northwest

While Northwestern states such as Washington and Oregon are located as far north as the Midwest, they tend to experience much milder winters. However, these states are also not known for ever getting very warm, with small fluctuations in temperature around the year. By mid-September, it will generally be too cold to swim, and you will need to start preparing to close your pool in the Northwest.

Rocky Mountains

The mountainous regions of the western USA create an interesting climate zone. Despite the northern part of New Mexico and southern Colorado being about in line with parts of the Southeast, these regions are far colder due to the higher elevation. By late September, the nights in the Rocky Mountains regions will drop close to freezing, and daytime temperatures rarely rise above 65 degrees. But as you travel further north to states like Montana and Wyoming, temperatures get colder, and you may need to close your pool sooner.

Alaska

Let’s talk about Alaska. Alaska is home to beautiful mountains and natural landscapes, but swimming pool weather is not something this subarctic state is known for. But with a proper pool heater, pool owners can enjoy a short pool season in the middle of summer. In terms of temperatures, even the southernmost parts of Alaska barely ever see temperatures above 75 degrees. The winter is also LONG in Alaska, lasting from late September to the end of May in some parts. Pool owners in Alaska will generally only keep their pool open from late July till September.

How to Close Your Pool

The swimming pool season is coming to a close, and it is time to get started on winterizing. Not entirely sure where to start? Don’t worry; I’ve got you covered.

• Test your water: Before anything, test your pool water. Even if you’re closing for just a few months, you need to prepare the water for a long, inactive spell so that algae won’t show up and make opening your pool a hassle. Test and adjust the water to reflect healthy chemical readings, balance any untoward agents, and shock the pool if necessary to clear any lingering contaminants.
• Clean the pool: Your pool is going to be hibernating for the winter, so before you allow it to rest, you should thoroughly clean it. Use a brush and vacuum to scrub off any debris and remove algae growth. Then allow your filter to run to get rid of any loose debris.
• Unhook and clean your equipment: Your equipment has to be cleaned as well. First, backwash and clean your filter and empty out the skimmer baskets. Then drain and unhook your filter, pump, and heater. The aim is to remove any debris and store your pool in as clean of a state as possible.
• Remove all other accessories: You should also remove any accessories in your pool (if possible). This includes removable ladders, steps, toys, and water features.
• Lower the water level: The water level should be lowered below the skimmer opening. This is to prevent the pool from freezing and damaging the equipment.
• Add the winterizing chemicals to the water: This will help prevent freezing and algae growth. If you live in an area with a lot of snow, you may need to add antifreeze to the pool.
• Cover the pool: The pool should be covered with a tarp or safety cover to protect it from debris and prevent evaporation. I recommend using a pool pillow to spread out and balance the weight of any ice and snow that fall on top of your cover.
• Check your pool periodically: Throughout the winter, check your pool to make sure it is still covered and free of debris or algae.

For a more detailed breakdown of how to winterize a swimming pool, check out my complete guide to winterizing your pool, winterizing your heater, storing above ground pools, and my winter pool care guide for off-season maintenance tips.

Time to Close Up!

Closing your pool for the season is one of the saddest times for any pool owner, but in most regions, it is necessary to prevent your pool from being damaged or filthy during the winter. The time of year when you should close your pool varies depending on where you live and your local climate.

Any questions about when you should close your pool and settle down for winter? Please reach out! I’ll be happy to chat and sort out any confusion you might have.