Cold snap brings early snow, high wind to Australia's southeast

Winter has come early to Australia with a cold front bringing high winds, snow and hail to the southeast in a cold snap the weather bureau says could last until the middle of the week.

Snow fell in Oberon, about 120km west of Sydney, on Monday, as the weather bureau warned sheep farmers across the southeast and in alpine areas that their animals exposed to the cold wet conditions could die.

"I didn't expect it to be this thick," Oberon resident Wendy Stanton said of the snow.

"It sort of started early yesterday afternoon and it just kept going and by the time I got up, everything was just covered in snow."

The Perisher ski resort received 10cm of snow over the past 24 hours, just over a month before the ski season is due to begin.

Temperatures along the east coast defied autumn and dropped below zero on Monday morning, Dean Narramore, senior meteorologist at the Bureau of Meteorology told Nine News on Monday.

Flights were delayed in Sydney after the airport closed two runways from late Sunday to just before noon on Monday due to strong winds, a Sydney Airport spokesperson said.

The cold front across the southeast began over the weekend with temperatures plunging well below the average for the month, according to the weather bureau, which forecast morning frosts would linger until early Wednesday.

The capital, Canberra, was dusted with snow on Sunday although it quickly turned to slush as temperatures rose through the day, according to videos shared on social media.