The forecaster said temperatures in the urban areas would be around 12 degrees on Sunday night, and it would be a few degrees cooler in the New Territories and on high ground.
It’s advising people to wear warm clothes, ensure adequate ventilation indoors and avoid exposure to wintry winds, especially on high ground and in exposed areas.
The Centre for Health Protection also urged people to keep warm, especially the elderly.
“Elderly people have less insulating fat beneath their skin to keep them warm and their body temperature control mechanism may be weaker. Their body may not be able to appropriately respond to the cold weather,” a spokesman said.
The Labour Department reminded employers to take appropriate precautions such as reminding employees who have to work outdoors or in remote areas.