Record-breaking deluge in Hong Kong wreaks havoc with 11-hour black rainstorm signal

Record-breaking torrential downpours hit Hong Kong on Tuesday and brought the city to a standstill with its second-longest black rainstorm warning, in effect for more than 11 hours, as authorities grappled with floods, many businesses had to close, and classes were suspended.

The Hong Kong Observatory said it had measured 358.8mm (14.1 inches) of rainfall at its headquarters in Tsim Sha Tsui as of 5pm, the highest daily rainfall in August since records began in 1884.

Residents have had little relief from the wet weather in the past week, with the black rainstorm signal being issued for a fourth time in eight days.

The highest-level rainstorm warning was raised at 5.50am, finally being downgraded to amber 11 hours and 15 minutes later at 5.05pm. All rainstorm signals were cancelled at 6.15pm, before another amber warning was issued at 10.55pm and then removed at 12.30am on Wednesday.

This made it the second-longest black rainstorm warning on record in Hong Kong, behind only another that was in effect for 16 hours and 35 minutes between September 7 and 8, 2023. The rainstorm warning system was introduced in 1992.

Authorities were forced to scale back many public services due to the heavy rain, suspending all school classes but opting against declaring the weather to be “extreme conditions”.