Temperatures on Hong Kong's highest peak plunged below freezing point in the early hours of Thursday as a severe cold snap gripped the SAR.
While temperatures dropped to nine degrees in urban areas and as low as seven degrees in parts of the New Territories in the morning, readings at Tai Mo Shan, some 955 metres above sea level, plummeted close to minus one in the early hours.
After briefly rising above freezing, temperatures at the mountain fell again to minus 0.6 degrees at 9am.
The Observatory issued the cold weather warning while the Centre for Health Protection reminded the public, especially elderly people and those with chronic health conditions, to protect their health.
Daytime temperatures on New Year's Eve are expected to reach no higher than 12 degrees, and the cold snap is expected to last for two or three days.
Freezing temperatures on Tai Mo Shan are rare but not unknown. In January 2016, firefighters had to come to the rescue of more than 100 hikers who wanted to see the ice first hand. Some 67 people were taken to hospital.