Classes of all AM schools and whole-day schools were suspended on Friday after the Red Rainstorm Warning Signal was issued.
Schools were told to implement contingency plans and arrange staff to look after students who might arrive and ensure that conditions were safe before allowing students to return home.
The warning was issued by the Hong Kong Observatory at 4:25 am.
This meant that heavy rain had fallen or was expected to fall generally over Hong Kong, exceeding 50 millimetres in an hour, and was likely to continue.
People who had to travel were advised to carefully consider the weather and road conditions and take necessary precautions.