Snow has fallen across central Victoria and parts of South Australia as an unseasonal wintry blast crosses south-eastern Australia on its way to NSW.

Temperatures fell as low as 1.4 degrees at Mount Lofty, the tallest mountain near Adelaide, on Friday morning.

Locals in the state’s Mid-North said they woke on Friday to some of the heaviest snow falls seen in many years.

By the middle of Friday, there were reports of more snow to as low as 200 metres above sea level in Victoria’s Otway Ranges and at Dunkeld and Ballarat in central Victoria.

Friday was forecast to be the state’s coldest September day in 20 years, with Melbourne reaching a top of just 12 degrees and Ballarat staying in single figures.

Weather bureau senior forecaster Keris Arndt said elevated parts of Melbourne might even see a flurry of snow around the outer north and Dandenongs.

And NSW won’t escape the unseasonal blast either, with temperatures to plummet on Friday night as the cold front arrives.

The Bureau of Meteorology’s Agata Imielska said the chill would persist on Saturday.

Tweet from @SarahJaneBell94

“In Sydney tomorrow we will wake up to some deceptively sunny conditions, but it will be quite windy and quite cool so it’s important to rug up and be prepared for those wintry conditions,” she said.

“We are expecting a top of 19 degrees, but it will actually feel more like eight or nine degrees.”

Showers and small hail are also possible for Canberra on Saturday, as well as snow in the high ranges down to 700 metres above sea level.

Back in South Australia, Whyte Yarcowie resident Judy Lewis said she woke on Friday to a white blanket over her car and front yard.

Ms Lewis said she could not believe it.

“I got up to make a coffee and I looked out and I thought ‘what’s all that white on the car?’ because it looked different to ice, which you get when it’s frosty,” she told the ABC.

“Then I looked on the back lawn – there was all white on the back lawn – and I thought ‘oh, wow, it looks like snow’ and then I got up and had another look and it was coming down.”

Tweet from @HDwyerRacing

Peterborough residents said it had also snowed there and was still coming down.

Ray Hotchin said he had seen snow only once in the town in his 11 years there.

“This one definitely the heaviest,” he said.

Bureau of Meteorology senior forecast Vince Rowlands said snow in September was “pretty unusual”, although it had been seen into October.

“We don’t often get snow in the Mount Lofty Ranges this late in the year,” he said.

Meanwhile, the first fire weather warning of the season has been issued in NSW. Some northern regions had heightened fire danger ratings on Friday.

-with agencies