Hong Kong experienced its highest daily rainfall for the month of August since records began in 1884, with the Hong Kong Observatory recording 358.8 mm
On 5 August, a total of 358.8mm was experienced by 17.00 at the Tsim Sha Tsui headquarters of the observatory. In some other areas up to 350 mm had fallen by early afternoon.
The highest “black rainstorm warning” (indicating 70 mm or more of rainfall per hour) was issued by the authorities and represented the fourth such alert in eight days, a record for the most frequent issue of such an alert in a single year. This warning remained in force for approximately 11 hours and 15 minutes through to 17.00 second only to the 16.5‑hour warning issued in September 2023. Rainfall rates peaked near 90 mm/hour, accompanied by over 9 600 lightning strikes recorded over a 7 hour period.
The intense rainfall was linked to a low-pressure system interacting with the southwest monsoon, creating conditions for extreme rainfall across the Pearl River Delta.
Widespread disruption was caused with submerged streets, stranded vehicles, and landslides across the city. Flooding at Hong Kong’s largest hospital, Queen Mary forced the suspensions of a range of services. It was also necessasry to close schools and the law courts. In addition transport services were affected with 20% flight cancellation rates and delays at Hong Kong International Airport, while speed limits were reduced on the Hong Kong-Zhuhai-Macau Bridge due to poor visibility. On-going transport issues saw roads damaged as a result of landslides.
