The Observatory issued its second Black Rainstorm Warning Signal this year as heavy rain continued to lash the region.
The black signal was issued at 12.55pm on Thursday, replacing the red signal which had been in force for 45 minutes.
"This means that heavy rain has fallen or is expected to fall generally over Hong Kong, exceeding 70 millimetres in an hour, and is likely to continue," the Observatory said.
Two amber signals were also issued on Thursday morning.
Members of the public are advised to take shelter in a safe place, and avoid travelling until conditions improve.
A Special Announcement on Flooding in the northern New Territories was also issued earlier, with rain especially heavy in Yuen Long, Sheung Shui and Ta Kwu Ling.
The Social Welfare Department said that childcare and elderly service centres, as well as rehabilitation service units and vocational training centres will remain open during their normal operating hours to take care of those in need.
The Education Bureau announced that students of afternoon schools do not have to attend classes today. It added that classes of evening schools will proceed as usual on Thursday night if no red or black signal was in force by 5pm.
Edited by Aaron Tam
