Cathay Pacific has warned that heavy rains in Hong Kong could impact flights.
The worst deluge to hit the Asian city in 140 years left streets under water with hourly rainfall reported at 158 millimetres.
The airline said in an online update: “Hong Kong is currently experiencing very heavy rain and thunderstorms.
“While our flights aren’t currently affected, this may change as the situation develops.
“We will continue to update the website with the latest information.”
The Hong Kong Tourist Board said: “Due to adverse weather, disruptions may occur in public transit and attractions. Please avoid outdoor activities and refer to relevant websites for updates.”
Hundreds of flights are reported to have been suspended in the wider Guangdong province, while local authorities advised residents in low-lying areas to consider evacuations.
The mainland city of Shenzhen – across the border from Hong Kong – reporting its heaviest showers since records began in 1952.