Snow blankets parts of NSW just weeks away from summer

Snow has fallen in parts of NSW after a cold front dropped temperatures and produced rain and storms.

A Thredbo local says the snow was "beautiful", but "unexpected" after a warm winter.

Suburbs that hit 30 degrees Celsius on Saturday dropped by more than 10C by the evening.

Parts of New South Wales have been blanketed in snow just a few weeks out from summer after a strong cold front swept along the state's coast.

David Crock from the Bureau of Meteorology said November was a "very volatile time of year", with the cold snap not that unusual, but was always "striking when it happens".

"We saw snow maybe down as low as 400 to 500 metres through parts of Tasmania yesterday, also snow on the Alps through Victoria and NSW down to about 800m," he said.

The heat in the north of the country, the senior meteorologist explained, coupled with a really cold ocean in the south was behind the change.

"So we've got that really strong temperature gradient between northern Australia and the Southern Ocean," he said.

"And that's what creates these strong cold fronts with a big push of cold air up through NSW and even into southern parts of Queensland."

On Saturday, Sydney hit 29.7C just after lunch time, dropping to 14C by the evening.

The massive drop was also experienced in Penrith, which went from 31.5C at 3pm, to 14C by late evening. Night time in Parramatta hit 13.C after sweating through 30.4 earlier in the day.

The change also brought heavy rain and storms.

Thredbo, in the state's alpine region, received a dumping of snow overnight when temperatures fell to -5.0 degrees Celsius.

It was 0C on Sunday morning and snow was still falling.

Madeleine McVie said while it was unexpected after a warm winter, it was "beautiful" and enough to build a snowman.

"It certainly was hard to get out of bed. It is very cold down here," she said.

"We got a little bit [of snow] a couple of days ago, and yesterday it started snowing about four in the afternoon.

People who had gone hiking at Mount Kosciuszko were ecstatic, she added.

"They certainly wasn't expecting it to snow down here in November.

"And we're prepping for our mountain biking season, so we weren't expecting it either."

On Sunday, cooler temperatures hovering between 10C and 12C degrees dominated across the state.

Strong southerly winds and hazardous conditions are forecasted along the NSW coast on Monday, with the chill expected to continue.