The Observatory on Thursday said the Standby Signal No. 1 will remain in force before noon and, with the tropical depression being about 500 km away, local winds are not expected to strengthen significantly.
But it said as the depression gets closer to the coast of western Guangdong, its outer rain bands will start to affect Hong Kong.
The Observatory said also warned of squally showers and thunderstorms and that, later in the day, winds would be strong both off-shore and on high ground.