When To Open Your Pool in 2026 (Based On Where You Live)
Matt Giovanisci 
April 8, 2026 You should open your pool when the outside daytime temperature stays consistently above 70 degrees Fahrenheit (or 21 degrees Celsius). 70 degrees is still a little too cold to go swimming, but it’s not too cold for algae.
As the weather starts to warm up, algae can start to grow in your pool water – especially if you use a mesh pool cover and the water is exposed to sunlight.
Springtime is also “pollen season,” and that can start collecting in your pool (here’s a guide on getting rid of pollen in your pool). So to help prevent algae and stop pollen from collecting in your water, open your pool and run your filter and pump when daytime temps are a steady 70 degrees.
This is the ultimate guide to keeping your pool sparkling clean throughout the year that contains everything you need to know about taking care of your pool the right way. Including saltwater pools.
What month should you open your pool?
We surveyed 1,900 pool owners and found that a majority of pool owners open their swimming pools between May 1st and May 15th.
In the U.S. pool industry, the unofficial start of the pool season is Memorial Day Weekend (end of May). That’s when pool stores are the busiest (at least in the northeast part of the country). It’s a good idea to open your pool before that to get a head start on the season and to beat the crowds in the pool stores.
Planning to open the pool yourself? Here’s how much it costs to open a pool.
What if you have a heated pool?
The same rule applies: you’ll still want to wait for consistent 70-degree weather. You just may not be able to swim in your pool if it isn’t heated.
Whether your pool is heated or not, plan on opening up your pool 2-3 weeks before you plan on using it. That’ll give you enough time to troubleshoot equipment and clear up any water chemistry issues.
If you don’t have a heated pool and want to learn more about how to keep your pool heated so you can open it earlier, check out our pool heating guide here.
What happens if you open your pool too early?
If your area experiences a surprising drop in temperatures after you’ve already started up your pool again, just leave the pump running and reinstall your pool cover until the weather warms up.
What is the first thing you do when you open your pool?
If you closed your pool correctly and opened it earlier in the season, then hopefully you’ll have clear water. The opening process is very easy.
- Fill up the water to the middle of the skimmer.
- Get your pump and filter system circulating again.
- Test the water.
- Add any chemicals needed.
- Swim!
If you want a more detailed explanation of what you need to do to open your pool, check out our guides on how to open an inground pool or above ground pool.
On the other hand, if you opened your pool and it’s either green or cloudy, you’ll need to check out our guides on how to get rid of algae and how to clear a cloudy pool.
Enter your water test results. Get a custom treatment plan. Know exactly what chemicals to add to keep your pool clear. Saltwater and hot tub compatible.
How do you know if the weather will stay above 70 degrees?
Start by checking out the historical weather averages in your area. Depending on where you live, you may hit the 70-degree sweet spot sooner than you think.
In the U.S., people tend to think about opening their pool around the middle to end of May. While this feels like a good time to start swimming, it actually might be too late to open your pool.
Remember, if the temperature has stayed consistently above 70 degrees, you could be opening up your pool to an algae nightmare. And if EVERYONE opens their pool at the same time, pool chemicals and equipment might be out of stock, and pool service companies might already be booked solid.
So, when it comes to opening up your pool, the sooner the better!
Key Takeaways
- Open your pool when daytime temperatures consistently stay above 70°F (21°C) to prevent algae growth and pollen buildup.
- Most pool owners open between May 1st and May 15th, but opening before Memorial Day Weekend helps you avoid crowds at pool stores.
- Plan to open your pool 2 to 3 weeks before you actually want to swim, so you have time to fix equipment and balance your water chemistry.
- If temperatures drop unexpectedly after opening, keep the pump running and put the cover back on until it warms up again.
- The basic opening process is simple: fill water to the skimmer, start the pump and filter, test the water, and add chemicals as needed.
- Opening earlier is almost always better than opening late, since waiting too long can mean algae problems and out-of-stock chemicals.
