El Niño Warning: What Melbourne Pool Owners Need to Know

The Bureau of Meteorology has confirmed that El Niño is underway, with current conditions already well above the threshold used to define an El Niño event.

For Melbourne pool owners, this is worth paying attention to. El Niño is often associated with warmer and drier conditions across parts of Australia, which can have a noticeable effect on how much water your pool loses, how quickly it uses chlorine and how much maintenance it needs.

The current event is also shaping up to be particularly strong. As of 13 September, the Bureau’s main El Niño indicator was sitting at +2.51°C, well above the +0.80°C El Niño threshold. Most of the climate models surveyed by the Bureau expect it to strengthen further through spring, with El Niño conditions likely to continue into autumn 2027.

So, what could that mean for Melbourne and your pool over the months ahead?

What Is the Weather Outlook?

While El Niño does not guarantee a hot, dry summer, it does increase the likelihood of certain weather patterns.

The Bureau’s current outlook points towards warmer daytime temperatures across much of southern Australia, while parts of south eastern Australia also have an increased chance of below average rainfall.

Interestingly, Melbourne has just come out of a wetter than average winter. Melbourne Olympic Park recorded 162.6 mm of rain, around 130 per cent of its winter average. Winter temperatures were also warmer than average across Greater Melbourne.

What matters now is the shift into spring and summer. If Melbourne experiences the warmer and drier conditions associated with El Niño, your pool can respond quite quickly.

What Can El Niño Conditions Do to Your Pool?

The first thing many pool owners are likely to notice is increased water loss.

Evaporation increases with factors including higher air temperatures, wind and reduced cloud cover. During extended periods of warm, dry weather, the amount of water leaving an uncovered pool can become significant. With less rain replacing that water, you may find yourself topping up more regularly.

That does more than change the water level. Regularly adding fresh water can gradually affect your pool chemistry, which means levels may need to be tested and adjusted more often.

Hotter weather can also increase chlorine demand. Strong sunlight breaks down chlorine, while warmer water, more frequent swimming and the extra contaminants that come with pool use can all increase the amount of sanitiser your pool needs.

If chlorine production or dosing does not keep up, water quality can deteriorate surprisingly quickly. Algae can take hold, the water can lose its clarity and getting everything back under control can require considerably more work than simply maintaining the pool properly in the first place.

Warm weather can also affect equipment. Pumps and filtration systems generally run for longer during summer, chlorinators work harder and filters may need more frequent cleaning, particularly during dry and windy periods when more dust and debris is entering the water.

What Should You Do Before Summer?

The best time to prepare is before we get an extended run of hot weather.

Start by having the water properly tested and make sure your levels are where they should be. If you have a salt chlorinator, check that the cell is clean and producing properly, and increase production rather than assuming the settings you used through winter will be enough for summer.

Your filtration time may need adjusting as well. Warmer water and increased swimming generally mean the pool needs more circulation and filtration than it did during the cooler months.

Most importantly, keep an eye on the pool rather than waiting for a problem to appear. Check the water level regularly, test the chemistry more frequently during hot weather and adjust your chlorinator and filtration as conditions change.

El Niño does not tell us exactly what Melbourne’s weather will do on any particular day, but the Bureau’s current outlook gives us a good reason to prepare for warmer and potentially drier conditions.

For your pool, getting ahead of those conditions can make a big difference. A pool that is balanced and running properly going into summer is much easier to manage when the heat arrives.

Bring a water sample into our store so we can point you in the right direction and prepare your pool for the warmer weather ahead, “because everybody deserves a safe and healthy pool”.