The Australian woman and her three adult sons who went missing overnight at a Japan ski resort have been found safe.

Japanese media are reporting that the the family dug themselves a snowhole to shelter from the cold overnight, which plunged to as low as -10º Celsius.

The woman in her 50s and her three adult sons were reported missing after she contacted a friend via Facebook to say they’d got into trouble.

“I’m skiing and I got lost,” she said, according to Japanese news site Mainichi.

Police said they believed the family were missing somewhere near the summit of the mountain at Nozawa Onsen ski resort, around an altitude of 1,600 metres.

The resort has seen about a 1.5 metres of snowfall over the past three days.

It is not yet known how the family came to be lost.

Photo: Twitter / Nozawa Holidays.