Only a few days after the most recent devastating floods in eastern Australia, thousands of people in the metropolis of Sydney were again asked to get to safety.
The authorities announced on Tuesday that heavy rain had led to new flooding, especially in the south-west of the country's largest city.
Numerous streets in the suburb of Camden, for example, were under water, and many schools in the New South Wales region remained closed.
There were evacuation orders for about a dozen suburbs.
Meteorologists warned of flash floods as a result of "intense rainfall and a very dangerous thunderstorm" specifically in Sydney and Hawkesbury and in the Blue Mountains.
The wet weather is expected to continue, said Dean Narramore of the Bureau of Meteorology.
"We have a tough 24 hours or even 48 hours ahead of us," Australian media quoted the expert as saying.
"And even if the rain stops on Wednesday and Thursday, the rivers are still flooding."
Meteorologists spoke of the wettest start of the year in Sydney since weather records began in 1858. Since January 1, almost 822 millimeters of rain have fallen: that is 822 liters per square meter.
The record for the same period was 783 millimeters in 1956. For comparison: the average rainfall over a whole year in Germany is 700 to 800 millimeters.
Since late February, a slow-moving low-pressure system had already caused historic flooding in many parts of Queensland and New South Wales.
More than a dozen people lost their lives.