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

Written by Michael Dean
August 16, 2023

when to open a swimming pool

The cold weather is finally ending, with snow dethawing and the temperatures rising. With summer around the corner, many pool owners wonder when to open their pools. If you jump the gun and open your pool early, you may be spending money on electricity and water to keep the pool running before it is warm enough to swim. On the other hand, if you wait too long to open your swimming pool, algae may begin to bloom and turn your pool green, making it much more difficult to open the pool and sanitize the water.

In this article, I will tell you the best time to open your pool according to your state and climate.

Main Takeaways

  • It is best to open your pool when the outside temperature is consistently above 70 degrees.
  • Pool owners in warmer regions such as Florida, Hawaii, Texas, and California may be able to keep their pools open all year.
  • In colder regions such as the Pacific Northwest, New England, and Alaska, the pool season may only last two months.

When Should You Open Your Pool?

You’ve closed your pool for the winter, and as the cold weather slowly starts to subside, you wonder, when should you open it? As a general rule of thumb, I recommend waiting until the outside daytime temperature is consistently above 70 degrees before you open it for the season. 70 degrees might seem cold for swimming, but it is warm enough for algae to flourish. So, this is the best time to open up your pool, get your filter running, and shock the water to prevent an algae infestation from starting. The last thing you want is to wait too long to open your pool and find green swampy water underneath your winter cover.

When Should You Close Your Pool?

You should close your pool when the weather is consistently below 70 degrees. If the temperature fluctuates in your region throughout the winter and never consistently drops below 70 degrees, I don’t recommend winterizing and closing your pool.

Most Americans open their pool at the beginning of summer, in May or June. But this depends on what area you live in. Obviously, the time of year that the temperature goes above 70 degrees can vary depending on your region. Read on to learn the best time to open your pool based on the climate in your region.

Best Time To Open Pool In Different Climates/Regions

Hot and Humid All Year

Keep your pool open all year

The main regions of the US that remain hot and humid all year round are South Florida and Hawaii. These are some of the most popular regions for pool ownership, as it is easy to keep the pool open all year round since temperatures rarely drop below 70 degrees. Most pool owners in this climate keep the pool open all year. Some close the pool for only a month or two during the coldest months of December and January and reopen in February when temperatures are more consistent.

Hot and Dry All Year

Close your pool in November and open it in March

The desert climates of the US are another region where many pool owners keep their pools open all year. These regions include west Texas, southern California, southern Arizona, southern New Mexico, and southern Nevada. While these regions do not experience much of a winter, the temperatures drop off during the winter months, especially at night. So, many pool owners close their pools in November and reopen them in March. Despite temperatures climbing to up to 80 degrees in winter, it can drop as low as 30 degrees at night in these desert climates, so keeping the water warm enough can be a struggle.

Hot Summers, Mild Winters

Close your pool in late October and open it in April

Most of the southern states in the US have hot summers and mild winters. Regions included in this climate are the Deep South, central and east Texas, north and central Florida, California, Arizona, New Mexico, and Nevada. These regions have a pretty long pool season, as the summers are much longer than the winters, and the temperatures rarely drop below freezing. These regions typically close their pools between late October to mid-November and will reopen them in early March to early April.

Hot Summer, Cold Winters

Close your pool in October and open it in May or June

Regions such as the midwest, New York, New Jersey, Pennsylvania, and Appalachia experience all four seasons during the year and have hot summers and cold winters. It generally starts to get consistently below 70 degrees in mid-September to early October, so pool owners will close the pool for the winter then and open it between late April and mid-June, depending on the temperatures. Pool owners in regions like Tennesee and North Carolina will likely open their pools sooner than in cooler states as the temperatures will warm up sooner.

Mild Summer, Cold Winters

Close your pool in mid-September and open it in June

States in this climate have a relatively short pool season as the temperature is really only warm enough for a comfortable swim during the hottest months. Regions in this climate zone include the Pacific Northwest, New England, northern Michigan, North Dakota, Minnesota, Wyoming, Montana, and Idaho. These states and regions experience bitter winters and warm, but not hot, summers.

The temperatures in these regions may only be above 70 degrees for 2 to 3 months per year, so pool ownership is low, and those with pools do not keep them open for long. The ideal time to close a pool for the winter in this climate is around mid-September, and the best time to reopen it is between late May to late June. In the coldest states, such as Washington State, Maine, and North Dakota, it is common for pool owners to only keep the pool open for July and August. Pool heaters are very common in these regions and can help extend the swimming season by a month or two.


Close your pool in early September and open it in July

Alaska and the high Rocky mountains are the only areas of the US that are considered subarctic. These regions experience extremely cold winters and rarely experience summer weather. The “summer” temperatures rarely get above 65 degrees, and the temperature quickly drops below freezing again in mid-September. So while hot tubs are pretty common in these regions, you will rarely find an outdoor pool. Those who do have outdoor pools in the subarctic will open them in late July and close them in early September, and even with a pool heater running, they will require a pretty high tolerance to cold water!

How to Open Your Pool

Opening your swimming pool is a very important step in prepping for the new pool season, and it will generally take a few days to get the pool water clear and safe to swim in. Here are some of the basic steps to opening your swimming pool.

  1. Clean and remove your pool cover
  2. Top up the pool water
  3. Remove the winterizing plugs
  4. Reconnect and start your filter
  5. Clean and shock your pool
  6. Balance the pH and chemical levels
  7. Let the filter run for 24 hours

For a more detailed breakdown of opening your pool, read my in-depth pool opening guide. And let me know if you have any questions!

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