Why Australia is being soaked when a record El Niño is forming

The paradox of rain during El Niño

El Niño is typically synonymous with drought in Australia, yet the country is currently being soaked by a series of rainbands. According to reporting by ABC Australia, 2026 is on track to become Australia's wettest El Niño year on record. The year began with widespread rain in February and March, which was not surprising given the active La Niña phase. However, even after a rapid transition to El Niño through autumn and an intensification toward an unprecedented event in winter, frequent rainbands have continued to traverse the country.

Year-to-date rainfall has set an all-time record for an El Niño year, with the national average already exceeding 400 millimetres. August, in particular, is looking impressive for an El Niño year. Through 27 past Pacific warm phases since 1900, the nation's average August rain has been a paltry 13 millimetres. Yet over the next five days, a mammoth cloudband is expected to engulf the southern two-thirds of the country, bringing one of the wettest Augusts on record to parts of South Australia, Victoria, and New South Wales.

Northern South Australian towns have already recorded their wettest August on record, including Arkaroola with 97 millimetres versus the previous record of 72 millimetres from August 1973. The Bureau of Meteorology's winter outlook issued in late May heavily favoured a dry season, but the season turned out wetter than normal.

The role of climate and ocean warmth

ABC Australia reported that climate change is increasing Australia's annual average precipitation, and this increase is enhanced in El Niño years. Senior climatologist Zhi-Weng Chua from the Bureau of Meteorology attributed the unusually wet conditions to warmer central Indian Ocean waters, which are about 1–2 degrees Celsius above average and forecast to warm further. These warmer waters increase atmospheric moisture and create favourable conditions for rain systems.

Mr Chua noted that during El Niño events, the southern two-thirds of Australia typically experience warmer-than-average conditions, and the exceptionally warm surrounding oceans may enhance the forecast warmth signal. The Bureau's spring modelling is confident that the western half of Australia will have a wet spring, while eastern states have mixed odds. The modelling also tips southern Australia to have mean temperatures up to 3 degrees Celsius above pre-industrial levels in the coming months.

A big low-pressure system on the move

In the immediate term, a large low-pressure system is building over eastern Western Australia and will bring rain to almost every state and territory over the next three days, as reported by 7NEWS Australia and The Canberra Times. Senior meteorologist David Crock (named by 7NEWS) said the system is drawing in moisture from the Indian Ocean and will bring quite a bit of rain across the country. The Canberra Times quoted senior meteorologist David Crockett (the same person, with a slightly different surname in that report) saying, "We will see a big low-pressure system bringing rain and storms across a vast area of southeast and central Australia over the next three days or so."

The system has already delivered widespread rain and thunderstorms across the west, western South Australia, and the southern Northern Territory, including 20–30 millimetres in Alice Springs. It is centred in far-west South Australia and will track along the coastline, bringing rain and storms to most of the state on Monday, with rain bands possibly producing 30–50 millimetres. There are fears of flash flooding in parts of South Australia, which are already quite wet. "Those areas are quite wet already," Mr Crock said. "They've had quite a bit of rain in recent weeks and months. So impact from that could be some pretty quick flash flooding."

The system is expected to move eastward into Victoria, New South Wales, and southern Queensland late Monday, with wild weather on Tuesday. Parts of Victoria could see 40–60 millimetres of rain or more on Tuesday, with concerns for areas of northern Victoria from previous rain events. The rain will add more water to river systems that flow into the Murray. There is a risk of severe thunderstorms through northern Victoria, much of western NSW, and southern Queensland, with heavy rain and damaging winds. By Wednesday, the system moves out into the Tasman Sea but continues to bring rain and storms to parts of the eastern half of New South Wales and southern and southeast Queensland.

Forecasting challenges and long-term outlook

The Bureau of Meteorology's winter outlook issued in late May heavily favoured a dry season, but the season has turned out wetter than normal. This discrepancy highlights the difficulty of seasonal forecasting in a changing climate. Historical data from ABC Australia shows that during 16 past moderate-to-strong El Niño events, winter rainfall decreased by an average of 32%, spring by 20%, and summer by 2%. Yet the current year has defied these trends so far.

While the immediate cause of the current wet weather is the low-pressure system drawing moisture from the Indian Ocean, the broader pattern of above-average rainfall during an El Niño year has been linked by ABC Australia to climate change and unusually warm ocean temperatures. The Bureau's spring modelling suggests the western half of Australia is likely to see a wet spring, while eastern states face mixed odds. At the same time, temperatures are expected to be warmer than average across southern Australia, with mean temperatures potentially up to 3 degrees Celsius above pre-industrial levels.

Perspectives

Bureau of Meteorology

The Bureau of Meteorology, through its senior climatologist Zhi-Weng Chua and senior meteorologists David Crock and David Crockett, attributes the current wet conditions to a combination of natural variability, a large low-pressure system drawing moisture from the Indian Ocean, and broader climate factors. It notes that climate change is increasing Australia's annual average precipitation, particularly during El Niño years, and that warm Indian Ocean waters are providing additional moisture. The Bureau also forecasts warmer-than-average temperatures in the coming months despite the rainfall.

7NEWS Australia

7NEWS Australia focuses on the immediate weather event, reporting on the large low-pressure system and its potential impacts, including flash flooding in already wet areas. The outlet quotes meteorologist David Crock describing the system as "pretty big" and drawing moisture from the Indian Ocean, with rain expected to reach every state and territory. The tone is one of alert and caution, emphasising the risks of heavy rainfall and thunderstorms.