Hongkongers on Monday were told the No 8 typhoon signal would stay in place until at least 4pm as Typhoon Talim, the territory's first typhoon of the year, passes the Pearl River Estuary.

As of 9am, the storm the centre of the storm was about 260 kilometres South to Southwest of the SAR and it was said to be continuing to intensify.

"Whether the signal No 8 will remain in force thereafter will depend on Talim's speed of departure from the Pearl River Estuary and the change in wind strength over the territory, as well as how persistent the gusts associated with the rain bands of Talim will affect Hong Kong," the Observatory said.

"Under the influence of Talim, east to southeasterly gales prevail over Hong Kong, with occasional storm force winds on high ground," it added.

The No 8 signal was first issued at 0.40am.

As of 6am the government call centre had received three reports of fallen trees, but none of landslides or flooding. The Hospital Authority said it had not received any reports of anyone being admitted to public hospitals because of storm-related injuries.

The fact that the storm warning will remain in place will mean many facilities remain closed all day, including banks and most government offices. There'll be no trading on the Hong Kong Stock Exchange for the day.

The Education Bureau had earlier announced that full-day schools would not open on Monday.

Transport has also been affected. The MTR Corporation is running a reduced service on most lines, with MTR Buses and in-town check-in for the Airport Express suspended.

Tram, ferry and most bus routes will also remain suspended throughout the storm. The Airport Authority has urged passengers to check the status of their flight before heading out.