El Niño Expert Q&A: Impacts on Australia and Preparation

By Hanan Dervisevic And that's where we'll wrap things up on the El Niño expert Q & A live blog.

Thanks so much for joining us and sending through all your questions. I'm sorry we couldn't get through them all.

While the Q & A might be over, the ABC climate team will continue to keep you up to date on all things weather so watch this space.

Have a great rest of your Thursday. Bye for now 😊

Will there be weaker trade winds on the Queensland coast? H By Hanan Dervisevic Can we sailors expect weaker trade winds on the Queensland coast? — Gary

Ahoy Gary,

ABC News Breakfast meteorologist Nate Byrne is excited to take this one:

Ah, a mariner after my own heart.

Yes, and the trade winds can break down altogether, or even reverse! Interestingly, we also tend to see stronger sea breezes that penetrate deeper — great news for some temporary relief from the heat on land, but a bit of a headache if you're sailing inshore during the afternoon.

On the other side of things, reduced cyclone activity may give you more days on the water later in the year.

My tip: check the BOM coastal waters forecast, make sure the outboard has enough fuel, and don't forget the oar … just in case. Wishing you fair winds and following seas.

Will Queensland be more prone to humidity? H By Hanan Dervisevic Does this mean constant high humidity levels in summer in Queensland? — Mary

Hi Mary,

I've got Climate Council's Andrew Watkins here to answer that one for you:

No, that's typically what occurs during La Nina, the opposite of El Niño.

El Niño tends to reduce the really humid air moving in from the Coral Sea, and we tend to see more air from inland Queensland at times, hence less humid overall.

That said, it's the wet season in the north, so there will be humid periods, noting that El Niño does typically mean a later start to the wet season as well.

How does El Niño affect our marine life? H By Hanan Dervisevic How does it affect our marine life? Coral bleaching, shark migratory behaviour etc. — Dominic

Hi Dominic,

ABC News Breakfast meteorologist Nate Byrne says this is a "GREAT" question. This is his response:

We tend to focus on what's happening in the atmosphere because that's where we live, but air is just a fluid that sits on top of — and interacts with — a literal ocean of fluid seawater. Just like in the air, we get warm fronts and cold fronts, heatwaves and jet streams in the ocean (is like weather without the rain!).

Even though the trade winds weaken during El Niño, we still get warm water off our east coast but a lot of it moves back into the central pacific. Warm ocean surfaces are a great source of moisture, so storms and rain we'd normally see instead start further east and run out of steam before they get to us — that's why our east ends up drier and with clearer skies.

Those blue skies allow more sunshine to warm things up and can lead to more ocean heatwaves. It's particularly bad because the oceans have been soaking up a lot of heat for a long time, so it doesn't take much more to make things deadly for species that are susceptible to temperature changes, like coral.

Migratory behaviour is a little harder to nail down (and outside of my wheelhouse!), but it can change the availability of food sources, for sure. Species like whales and sharks tend to follow the food! Those smaller food sources are often very sensitive to changes in temperature and salinity, and have fairly narrow margins of safety when it comes to change.

How can those vulnerable to the heat stay safe? H By Hanan Dervisevic I'm 80yo, how will this affect me and others of my age? — Geoff

Here's Climate Council's Andrew Watkins tips:

G'day Geoff, that's a great question.

Both El Niño and climate change raise the risk of heat extremes during the summer, and for the very young and for people with a few years more than most under their belt, this can present some challenges, as for both groups their natural tolerance of heat is reduced.

Like any summer, its important to stay in cool places when it gets hot, drink more, and never be afraid to ask for a hand if you need it.

If you are in the bush, have a fire plan where you give yourself more time to leave, and keep your phone charged. Really, its about using all that common sense you've accumulated to keep yourself safe when the extreme days come along.

How do strength and severity interact with one another? H By Hanan Dervisevic G'day, is it true that the strength of the El Nino doesn't directly relate to the severity? So the fact that it will be the strongest on record doesn't necessarily mean it will be the most severe in terms of drought? Also — isn't the Negative IOD in some ways more important and if that keeps up then it will counteract the El Nino? I believe El Ninos and Negative IODs are quite rare together? — WeatherNuffy

Hi there WeatherNuffy,

Thanks for joining us on the blog.

Here's ABC News Breakfast meteorologist Nate Byrne with an answer:

Totally correct — strength doesn't correlate very well with intensity, but it does have an influence for us. One of the main concerns is if the strength allows it to carry on through summer (when El Niño typically breaks down) and last longer.

The Indian Ocean Dipole (kind of like the El Niño Southern Oscillation, but to our west) and the Southern Annular Mode (another climate driver, but to the south) tend to have more of an influence during summer, but El Niño still factors in.

A negative IOD usually increases rain, and they rarely coincide because the two oceans are interconnected, but it has happened before.

And the Climate Council's Andrew Watkins has joined in too:

Yes, the IOD is very important for winter and spring rainfall, for some places on a par with El Niño and climate change.

At the moment, the influence from the Indian Ocean via the IOD is not boosting the El Niño impacts, as the IOD is neutral (not negative though) but most models have the IOD going to a positive state in July or August. If that happens, El Niño in the Pacific, the positive IOD in the Indian Ocean, and climate change will all be pushing winter and spring into hotter and drier conditions. A triple whammy!

Is climate change making El Niño more extreme? H By Hanan Dervisevic I don't understand the relationship between El Niño and climate change? I know El Niño events are bad but aren't they cyclical? — Carolina

Hi Carolina,

Here's an in-depth answer to your question from the Climate Council's Andrew Watkins:

Yes, El Niño are cyclical — they occur every 2-7 years. But it's their impacts that are being supercharged by climate change because of the extra heat put into the atmosphere and into the oceans. This is making the extremes associated with El Niño events more significant, as they (fires/drought/heat) have a greater risk of occurring in any year now due to climate change, and El Niño boosts that risk even higher.

Scientists are still working to fully understand the interaction between the pair. El Niño is a natural, periodic shift in Pacific Ocean temperatures that alters global weather patterns for several months.

But in recent decades, we are seeing more of the stronger events, and more of the multi-year events as well.

One thing is certain — climate change will compound all of the impacts that El Niño brings. We are entering El Niño from a baseline that is 1.5°C hotter than pre-industrial levels thanks to our burning of coal, oil and gas.

So if El Niño brings heat, climate pollution will make it even hotter. And with every degree of global warming meaning the atmosphere can hold at least 7 per cent more moisture, there is a greater chance of extreme rainfall if we do occasionally get weather patterns that bring storms, or as the rains come back when the El Niño breaks down in autumn.

You can see from this graph how temperatures under both El Nino and La Nina have gotten warmer over recent decades.

Will Perth be impacted? H By Hanan Dervisevic Most of the predictions I see are for Eastern Australia, what can we expect in Perth? A hotter than normal and drier summer? — Patrick

Lucky you, Patrick, both our experts have provided an answer!

Here's what ABC News Breakfast meteorologist Nate Byrne says:

That's because the impacts wane as you look further west, but for Southern WA it is certainly still slightly warmer and drier than average during El Niño years.

The bigger driver for the west is the Indian Ocean Dipole (IOD), but drier positive IOD years do tend to coincide with El Niño years more often than negative ones, which can make things much worse.

And here's Climate Council's Andrew Watkins:

With El Niño comes bigger high pressure systems over Australia, and in winter and spring that can mean more easterly winds for the southwest of WA. That means warmer days, warmer nights and less rainfall. SW WA has experienced around a 16 per cent decline in April to October rainfall since the 1970's, and El Niño can amplify this.

How can you prepare for El Niño? H By Hanan Dervisevic Can I do anything to prepare my home/lifestyle to weather the impacts of El Nino? I live in regional NSW — BC

Great question, BC!

ABC News Breakfast meteorologist Nate Byrne has given you a few helpful things to think about:

The best preparation you can do is to make sure that you get all those pre-summer jobs done before summer arrives:

Clear fuel from around your home

Start to think about managing water stores carefully on your property in the months ahead

Clean those gutters before fire season

Make sure you and your family have your emergency plans in place

We won't know about the summer bushfire outlook for a few months, but it never hurts to be ready, just in case.

Also, just because it's El Niño doesn't mean that everything is going to fall apart. Nevertheless, I think a lot of people underestimate the value of a little bit of peace of mind!

Will it makes our droughts worse? H By Hanan Dervisevic Do we assume we're facing droughts over the next few years? — Mohamed

Hi Mohamed,

Thanks for sending through your question! Here's Climate Council's Andrew Watkins with a response:

El Niño usually brings lower rainfall and higher temperatures/drier air to Australia, the key ingredients for drought. When you add in extra warming from climate change, we can expect the landscape to become dry due to low rainfall and higher evaporation, especially in spring going into summer.

This is very worrying for parts of Australia that have already had lower rainfall this year — including parts of NSW and Queensland, Tasmania, western Victoria and parts of WA.

I need to point out this doesn't mean no rain at all. In our warmer atmosphere, if rain does come, it's likely to arrive in short, intense bursts that can cause flash flooding rather than soaking into parched soil.

At the moment we can only look ahead for the current El Niño, which typically would peak in summer and end next autumn 2027, so we can't say for sure that dry conditions, if they emerge, would extend beyond that.

But if the soils get dry and rivers get low, we would actually need above average rainfall in 2027 to recover, so we always need to be cautious if drought emerges because they don't always disappear overnight.

When will El Niño end? H By Hanan Dervisevic How long is it anticipated to last for? — Kim

Hi Kim,

Lucky you, both our experts have provided an answer!

Here's what ABC News Breakfast meteorologist Nate Byrne says:

We can't be certain at this moment in time — a quirk of computer modelling is that inaccuracies grow faster the further into the future you look.

At this stage, it looks like it will last at least into 2027, but it could go significantly longer.

And here's Climate Council's Andrew Watkins:

Typically El Niño events peak in summer and end in the autumn, so we can expect this one to be locked in for several months now.

But their peak impacts are really in winter and spring. That said, climate change is boosting events these days and we are seeing more multi-year events than we did in the past. So in short, El Niño is here until at least early 2027, but we can't rule out further impacts well into next year.

Will Australia still get cyclones? H By Hanan Dervisevic Are we likely to see more TCs during summer with this climate swing? — Nick

Hi Nick, looping in Climate Council's Andrew Watkins to answer this one for you:

Another great question.

We usually expect there to be fewer cyclones during an El Niño year as the waters to our north are not quite as warm as in La Nina years.

Climate change is also reducing the frequency of cyclones. However, if we do get any cyclones, they could be stronger. That's because a warmer atmosphere can carry more moisture, and it's the energy carried by the evaporation process that fuels our tropical cyclones.

When was the last El Niño event in Australia? H By Hanan Dervisevic ABC News Breakfast meteorologist Nate Byrne is now taking us back in time to the last El Niño event we saw in Australia:

I reckon some people think back to the 2019/2020 Black Summer, but that wasn't an El Niño (it happened after an event in 2015-2016, followed by years of drought).

The latest El Niño was in 2023-2024. It started in mid-2023 and developed as a moderate to strong El Niño that set the record for Australia's driest 3 months (from August to October), but then it weakened and the summer brought the east a bunch of rain events, bringing devastating floods even as El Niño carried on.

It dissipated in April 2024. Because of the quick swing, we didn't see a lot of the long-term impacts of an El Niño, so many people in Australia didn't really even notice. That wasn't the case across the board, and certainly not the case overseas.

Could we be in for a summer of severe heat? H By Hanan Dervisevic Will it be much hotter this summer across the country? — Richard S

Hi Richard, thanks for your question.

Here's what ABC News Breakfast meteorologist Nate Byrne has to say:

It's certainly possible, but that hasn't always happened in El Niño years beyond what we normally get.

The likelihood of heat in the south is increased, and we do tend to get more heatwaves. Interestingly, it's partly because we generally see fewer cyclones, which can knock a lot of heat out of the tropics (and often deliver much-needed summer rain).

That's not to say we won't see cyclones, though — Australia has never recorded a year without a cyclone crossing the coast.

The increased heat and heatwave risk can also worsen our bushfire outlook, but that also depends a lot on other factors including our cool season preparation and hazard reduction.

How do the different states and territories experience El Niño? H By Hanan Dervisevic Ho