The Hong Kong Observatory downgraded the T3 signal to a T1 at 10.20pm on Thursday as tropical depression Toraji continues to weaken and moves away from Hong Kong.

At 10pm, Toraji was estimated to be about 150 kilometres south-southwest of Hong Kong, and is forecast to move west slowly across the seas south of the Pearl River Estuary.

The forecaster said it will drop all typhoon signals when Toraji no longer poses a threat to the SAR.