The Hong Kong Observatory said on Sunday afternoon that the Standby Signal No 1 will remain in force until at least 8 pm, but it no longer plans to issue a higher signal.

Forecasters said the tropical depression is gradually moving away from Hong Kong, maintaining a distance of more than 600 kilometres away from the SAR.

"The tropical depression is expected to skirt the southwestern coast of Hainan Island [on Sunday night] and will move further away from Hong Kong," acting senior scientific officer, Chong Sze-ning, said.

"The observatory will then consider replacing the Standby Signal No 1 with the Strong Monsoon Signal."

However, Chong said heavy rain and strong winds could still affect Hong Kong on Sunday night and Monday morning.

She said showers will be heavy at times and seas will be rough with swells, and members of the public should refrain from engaging in water sports.