What is Best Month to Open Your Pool? You May Be Surprised

“What Month Should I Open my Pool?”

Find out exactly when the best month to open your pool is depending on your equipment, your needs, and where you live!

enjoying a pool opened during the best month of the year

As the snows melt and temperatures begin to rise, many pool owners find themselves asking the same question:

“What Month Should I Open my Pool?”

There’s a lot to consider so we are going to unpack everything for you to make your decision a little easier.

So whether you have a simple above ground pool you leveled and installed yourself, a massive custom inground pool, or just a little plunge pool out back, you’ll know exactly what month to open your pool.

So clean that concrete deck and get out the patio furniture because you may just be be opening your pool in no time!


Why it Matters What Month you Open your Pool

The time of year that you open your pool is really important. There are issues on both sides with opening too soon or too early.

a woman swimming in a just opened pool

There are many factors to consider:

  • What region of the country you live in and what the daily temperature range is in a given month.
  • Whether you have a heater, and whether it is gas, electric, or solar (and how long you want to pay to run said heater).
  • Whether you have a mesh cover (which will let in lots of spring sunlight causing rapid algae growth underneath) or a solid cover (which will not).
  • How much time you have to deal with cleaning and sanitizing the pool once it is opened. (The later you open it, the more algae growth you will likely have to deal with)

The following factors need to be considered when you think about opening your pool.

Not sure where to start? Make sure to also check out our Step by Step Guide to Opening an Above Ground Pool!



Mother Nature

Mother Nature is the biggest reason why timing matters.

storm clouds forming above a swimming pool

Every year brings a different year of weather, and that weather needs to be tracked and considered when you’re opening your pool.

Look at the 10-day forecast to get a better gauge of why the timing matters.

You might see two days in the 70s followed by 8 days of sub-50s weather.

Knowing how the next two weeks will shape up is a good way to know when to open your pool.

If you open too soon, then you won’t be using your pool thanks to freezing weather.



Algae is a silent threat to your pool. It starts to grow when temperatures are over 70 degrees, and it loves growing in pools with mesh covers.

algae forming on the surface of a swimmign pool

The longer you wait, the more algae will pile up in your pool. It’s really hard to deal with algae, so the best course of action is to avoid it growing altogether.

Algae won’t grow as long as there’s not direct sunlight hitting your pool, or the water has been shocked with chlorine and sanitized.

So you can choose to wait longer if you have a solid pool cover which doesn’t let in any sunlight.



Some parts of the country have real problems when it comes to pollen.

pollen floating into a just opened swimming pool

Once trees and flowers start blooming and looking beautiful, it’s too late. Pollen is already making its way into your pool and flooding your water.

It’s hard to deal with pollen when it’s already in your pool, and if you have a mesh cover, the pollen will make its way into the standing water as it falls.

When your pool is open and the pump is running, pollen and algae will naturally be dealt with in the filter.


The Beauty

What’s more beautiful than looking out the back window of your house and seeing your glistening pool catching glimpses of the sun while the water ripples?

a man swimming in a pool

Having a closed pool can be an eyesore for your backyard.

The tarps and tie-downs can ruin the aesthetics of your backyard.

The best way to present your backyard is to have an open pool! This is another reason why opening too late might be an issue.


The Price

The later you open your pool, the more money you’ll spend on cleaning it. If you are good at cleaning your pool and with keeping the price for pool maintenance low, then you’ll want to opt for an earlier opening date.

Not only do you have to spend time and money on the cleaning, but you’ll also be faced with adding more chemicals to get your pool ready.

These costs add up and can be avoided by opening sooner rather than later.

However, if you open your pool too early your costs to run the pool pump and heater may add up much quicker than any cost related to cleaning algae out of your pool.

If you live in a southern climate where you won’t need to run the heater in early spring, then its no problem.

In northern regions where you may be running the heater until May or June, it gets pretty expensive if you open your pool 2-3 months before this.


How Much Use It’ll Get

When you open your pool, you can expect about three or four weeks to get the chemicals and cleanliness perfect before you’re ready to swim.

kids swimming in a pool

If you decide to open your pool in the middle of summer, you might miss out on all of the prime swimming days.

If you enjoy lounging by the pool or swimming laps, you’ll need to carefully consider when to open your pool. That begs the question – what month should you open your pool?

Not sure where to start? Make sure to also check out our Step by Step Guide to Opening an Above Ground Pool!


What Month Should I Open My Pool?

The rule of thumb is that you want to open your pool when mid day temperatures are consistently in the 70s.

This might be too chilly for most swimmers, especially if you don’t have a heater, but it’s the temperature that algae starts to grow.

Additionally, electric heat pumps will not work when the ambient air temperature is below about 55°F.  So if you have an electric heat pump, don’t plan on running it when temperatures are still dropping below 55°F at night.

If you have a gas powered heater, you can use it at any temperature you desire, but expect a nice sized gas bill to come with it.


The Best Month to Open a Swimming Pool

Taking all the above factors into consideration, the best month to open your pool will ultimately vary and come down to the region in which you live.

Regardless of where you live, you want to wait for when temperatures start rising.

Remember, it will be about 3 weeks from pool opening until the water is clean and safe before you can expect to use your pool so you should factor that into when you open your pool.

Here is the best month to open your pool depending on your region in the States.

For simplicity sake, let’s look at the US cut into thirds horizontally. The result is a southern, central, and northern chunk of land to consider.


Southern Third

People in Florida and along the southern Californian coast are probably scratching their heads and wondering what a “closed pool” means.

Southern states are hotter than northern states, so they have more freedom when it comes to opening their pools.

Some folks in southern florida even keep their pools open year-round, especially if they have a heater.

For everyone else, the most common month for southerners to open their pool is April.


Central Third

As you move further north, things get a little colder.


The central third of Americans need to be a little more careful about their timing.

States like Colorado and Utah tend to open their pools in May when the weather starts to shift.


Northern Third

The northern third has the latest time to open the pool. In states like Maine, a pool might not even be an option thanks to the short season and relatively chilly summer evenings they can have.

For a majority of Northerners, June is the best candidate for opening the pool.

The temperatures are finally warm enough to enjoy a warm sunny day at the pool.

Not sure where to start? Make sure to also check out our Step by Step Guide to Opening an Above Ground Pool!


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