El Niño declaration is finally here: What you need to know

The Bureau of Meteorology has formally declared an El Niño weather system is underway — two months after it was forecast by the World Meteorological Organization. With phrases like El Niño and La Niña tossed around a lot in Australia over the last few years, here's what they mean, and how Tuesday's announcement will affect our day-to-day lives over the next few months.

What you need to know

• Weather bureaus have warned Aussies now is the time to prepare properties against the risk of bushfires, which are expected to threaten large parts of the country.

• Australian officials formally declared that El Niño is underway on September 19, with warmer and drier conditions predicted for most of Australia over the next few months.

• Queensland, NSW and the Northern Territory are among the jurisdictions expected to cop the brunt of the extremes.

• Other factors, including a positive Indian Ocean Dipole, on top of climate change, will exacerbate conditions.

• El Niño is literally translated to 'little boy' in Spanish and refers to the warming of the ocean's surface in the central and eastern Pacific Ocean, in other words, he turns up the heat.

• La Niña however, refers to the opposite. Translating to 'little girl', the system cools ocean surface temperatures and is associated with increased rainfall. The pair are two of our main climate drivers.

Why I should care

If you live anywhere near areas prone to bushfires or aren't a fan of sizzling, above-average temperatures, then El Niño might spell bad news for you. Australia's last El Niño was in 2019. It was the country's hottest year on record and led to the Black Summer bushfires when more than 3,000 homes were lost and 34 people died.

Speaking to Yahoo News Australia, meteorologist Caitlin Minney said just last week that pretty much everyone in the country will feel the effects of the warm and dry weather.

💬 Conversation starter

Though El Niño will bring heat, it doesn't guarantee a shocker of a fire season, only that the risk will be increased. After three back-to-back years of La Niña, damns are still full and the ground is still reasonably moist. And while the grass and forest has grown quickly, more drying is required to turn all that into fuel.

Experts have warned however that this summer "will be hotter than average and certainly hotter than the last three years.”

🗣️ What they said

Dr Karl Braganza from the BoM: “We have been waiting for the atmosphere to couple with the oceans. The oceans have been in El Niño pattern for a couple of months. In the last two weeks, we have seen the atmosphere over the tropical Pacific respond to that pattern...that’s the sort of thing that sustains an El Niño event out until autumn.”

Climatologist Caitlin Minney: "During an El Nino, we would expect mostly eastern Australia to have lower rainfall and southeastern Australia to have higher maximum temperatures."

The CSIRO: "No two El Niño or La Niña events are the same. It’s important to note extreme events like drought and floods can happen in the neutral phase. It’s best to think of El Niño as ‘weighting the dice’. While it might make certain events such as high ocean temperatures more likely, it all comes down to the flavour, strength, and timing".

🗞️ For more on El Niño and La Niña

• Australia is set for a hot, dry El Niño. Here’s what that means for our flammable continent

• Climate change will jump to a whole new level in 2024 thanks to El Niño

• El Nino alert issued for Australia

• 'Cause for concern': Warning of brutal months to come for Aussies

• La Nina's brutal weather: The good, the bad and the ugly

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