Last of the summer rain puts southern states on flood watch and Sydney on alert for bull sharks | Australia weather

Late summer rains are wreaking havoc across Australia, with South Australia under flood watch, Victoria cleaning up after a downpour and Sydney issuing a shark warning after heavy falls.

Almost all of South Australia, much of western Victoria and parts of western New South Wales were under flood watch as a slow-moving pressure system from central Australia moved east. Queensland also experienced heavy rain.

Parts of Victoria received more than double their average February rainfall on Friday.

Meanwhile, sustained rain in Sydney over the past few days has led to official warnings that murky water conditions may increase bull shark activity.

South Australian Prime Minister Peter Malinauskas warned residents to prepare as heavy falls of 50 to 100mm were forecast for much of the state, with flash flooding possible in Adelaide when the system arrived in the capital on Saturday.

“It’s not unusual in South Australia or the Adelaide metropolitan area to see a 10 millimeter rain event,” he said.

“But when we start to see rain events north of 50, 60, 80 mm, that starts to represent the kind of conditions where we will see flash flooding.

“If we see this volume of rain in a short period of time, then we should anticipate flash flooding across the state.”

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The Eyre Peninsula has seen severe falls since Friday morning, with 71mm at Ceduna, 68mm at Wudinna and 98mm at Minnipa, the Bureau of Meteorology said.

Moomba, in the state’s north-east, received almost 100mm this week and 189mm in February – exceeding its annual rainfall average of 176mm.

Senior meteorologist Dean Narramore said the rain was badly needed for large parts of the state, which are battling long-term precipitation shortages.

“South Australia has been so dry for so long that this would be welcome,” he said.

“I think in general it’s good news aside from the flash flooding.”

In Victoria, 96mm was recorded at Horsham Airport on Friday night, around five times the regional city’s average rainfall for February of 19mm. Warracknabeal received 49mm, more than double the average February rainfall, while areas around Mount Macedon and Gisborne experienced hailstorms.

Melbourne was expecting good weather on Saturday but showers could start on Sunday before heavier falls on Sunday evening and Monday.

In Queensland, severe falls continued in inland areas. The outback town of Birdsville, where the average annual rainfall is 162mm, has received 178mm so far in 2026, with 128mm falling on three days this week.

Narramore said rain lashing South Australia was expected to continue through the weekend before moving into western New South Wales and western Victoria before the system weakened by midweek.

Narramore said a monsoon trough over northern Australia would strengthen through the weekend “bringing widespread rain, falls and possible flooding”.

“We could also see a tropical depression developing in northern Australia next week,” he said.

In eastern NSW, the Minns Government urged swimmers and surfers at beaches and waterways to exercise caution as recent heavy rain could create murky conditions that would increase bull shark activity in Sydney Harbour, other estuaries and along the NSW coast.

“If your local beach is closed due to weather, shark sightings or poor water quality, we are asking beachgoers, swimmers and surfers not to enter the water for their own safety,” NSW Regional Minister Tara Moriarty said.

“If you are on the coastline, near port or on waterways, it is important to understand how the environment can influence shark behavior and then take the necessary steps to reduce the risk of interaction with sharks.”

Four attacks took place in the state earlier this year, including one on Sydney Harbor which left a 12-year-old boy dead.

The climate crisis makes Australia more vulnerable to extreme weather and natural disasters, including intense rainfall. In 2025, the third warmest year on record, global surface air temperatures averaged 1.48°C above pre-industrial levels. For every 1°C of heating, the atmosphere can retain 7% more humidity.