It may be Spring, but parts of south-east Australia have recorded their coldest September nights in more than a decade.

A cold air mass, combined with clear skies, light winds and the recent lack of rainfall, has caused the mercury to plummet in multiple states, said Weatherzone meteorologist Ben Domensino.

“Victoria’s Nhill Airport registered its lowest temperature in three years (this) morning, dropping to -1.2 degrees Celsius just before 6am – this was also the coldest September night in more than 15 years,” he said.

“Elsewhere, South Australia’s Hindmarsh experienced its coldest morning this late in the year for 15 years (with 4.3 degrees Celsius).

“Meanwhile Coldstream (-0.2C) in Victoria and Sheffield (-0.5C) in Tasmania had their coldest morning this late in the year since 2010.

“On Monday, Australia’s highest weather station, Thredbo Top Station, dropped to a numbing -9.7 degrees. This was Australia’s lowest September temperature in five years.”

In Canberra, the frosty conditions also continued overnight with the Perisher Valley recording a low of -4.7 degrees just after midnight and both mount Ginini and Braidwood experiencing -3-degree weather just before 4am.

Further north however, the cold was less brutal in Sydney. The chilliest parts of the city this morning were in the western suburbs where temperatures dropped to between three and six degrees up to 5am.

With the AFL and NRL Grand Finals both to come this weekend, all eyes will also be set skywards in the days leading up to the games in the hope of perfect match day weather.

For the rest of this week, Melbourne is expected to receive a mix of sunny and cloudy weather with conditions up to a maximum 23 degrees on Thursday. 

Despite that, the Bureau of Meteorology has predicted a 70 percent chance of some rain on AFL Grand Final Day, some slight winds and a maximum temperature of just 13 degrees.

Sydney will also follow a similar pattern this week, with seasonally warm weather of up to a maximum 28 degrees by Friday, however the weekend is looking a little damper with a 60 percent chance of up to 8mm of rain on Sunday.

Elsewhere in the country, the cold front affecting the south-east isn’t looking like it will have much of an effect on the rest of the week. 

Despite a chance of some rain towards the weekend, Brisbane is expected to receive warm, partly cloudy conditions and temperatures of up to 28, while Darwin will stay mostly sunny as the mercury soars to 35 this weekend.

Darwin's steamy weather also come as the city received its heaviest rain in six months today during a rare September shower that dumped 29.4mm in just an hour over Darwin Airport just after midnight.

That figure marks the highest daily rainfall total in Darwin since March and nearly double the monthly average for this time of year, according to Mr Domensino.

In Perth, the weather still stay around the 23-degree mark despite some cloud, although a chance of showers building over the weekend is predicted.

Most of the colder conditions should pass Adelaide by tomorrow as well, with a 25-degree day predicted, followed by a string of cloudy days leading into the weekend.

After this morning’s chill, Canberra’s weather will warm up again over coming days despite some cloud cover, while Hobart may be a little damp heading into the weekend due to a string of rainy days to come and a cloudy weekend ahead.