Australians shiver through an unseasonal change

Freezing temperatures and record daily rainfalls have left Australians shivering through an unseasonal start to spring.

Parts of the east-coast woke to their coldest September mornings on record, with Canberra mercury dropping well below freezing to -6.9 degrees on Monday.

Queensland and South Australia also recorded historical lows, with Adelaide shivering through its coldest September morning in a century.

At the other end of the country, record-breaking rainfall saturated pockets of the top end as a low pressure system swept across the Northern Territory.

The record lows were caused by a cold front that swept across much of the east coast and has brought a low pressure band through the centre of the country and into the top end.

Some Territorians woke to a heavy downpour and plummeting temperatures on Tuesday, by noon, the mercury had risen to just 23 degrees in Darwin, despite recording 35 degrees just days before.

A low pressure system stretching from Darwin to Brisbane is predicted to bring above average rainfalls in the coming days.

Bureau of meteorology senior forecaster Rebecca Patrick said the unusual rainfall in the NT marked the end of the beloved dry season.

"We do often get some rainfall in September, but it's not a frequent occurrence," she said.

"We have set some records across parts of the top end for daily rainfall amounts."

Ms Patrick said in Darwin's north, the gauge at Nightcliff pool recorded 75.2mm overnight breaking September daily rainfall records.

However, the highest rainfall was recorded in Howley Creek, 150kms south of Darwin, with 78mm recorded.

While the downpour caught locals by surprise, Ms Patrick said the unseasonal event would not mean a reprieve from the oppressive build-up season.

"You could not call the one event an indicator, but it is a sign that we are transitioning towards the wet season," she said.

The tropical humidity is now expected to build as Darwin prepares for cyclone season.