A rare black rainstorm warning was issued by the Hong Kong Observatory at 8.10pm, due to heavy rains accompanied by lightning and flooding.
Seventy millimetres of rain has fallen in an hour.
A thunderstorm warning issued at 1:00 p.m. will be effective until midnight. Frequent squally thunderstorms are expected. The HKO said intense gusts reaching 70 kilometers per hour or above may affect Hong Kong.