The Hong Kong Observatory issued an Amber rainstorm warning on Sunday night due to heavy showers expected from an active monsoon and low pressure trough.
The warning was issued at 9.40pm on Sunday. It signals that more than 30mm of rain had fallen or was expected within an hour across the city.
Unsettled weather is forecast to continue under the influence of a southwest monsoon and trough of low pressure. Showers are expected to be particularly heavy until Tuesday.
The Observatory urged the public to take precautions against flooding. Residents should avoid low-lying areas and secure outdoor items.