Residents in low-lying areas of the city were on the alert or had left their homes for safer ground last night as Typhoon Koppu approached the city with winds of up to 120km/h.
Officials warned that Koppu was expected to bring gale-force winds and outbreaks of heavy downpours - and perhaps an extra day off - to the city today, with it coming closest to Hong Kong in the early hours of the morning.
At midnight, Typhoon Koppu was about 150km south-southwest of Hong Kong and forecast to move at about 18km/h towards western Guangdong.
The Observatory warned that low-lying areas could face serious flooding and urged residents to be on the alert. The Home Affairs Department also advised residents of low-lying areas of Tai O on Lantau Island to leave their homes for safety's sake.
Schools were ordered to close in the afternoon as the weather deteriorated and ferry services to outlying islands were suspended early in the evening. There was no major disruption to air traffic but Cathay Pacific warned of possible delays.
Two lifeguards at St Stephen's Beach in Stanley had to be led to safety by marine police boats after they became stranded in rough seas while patrolling on a canoe.