The Department of Environment says air quality is deteriorating, particularly in the western part of the peninsula.

The heavy rain comes as the city is still repairing damage caused by torrential rain linked to typhoon Haikui which passed nearby in recent days.

Scientists warn that typhoons hitting China are becoming more intense and their paths growing more complex, escalating risk of disaster.

The weather bureau has issued the highest 'black' rainstorm warning and said more than 200mm of rainfall was recorded on Hong Kong's main island, Kowloon and the northeastern part of the city's New Territories.

The summer rainfall deficit could make essentials such as sugar, pulses, rice and vegetables more expensive and lift overall food inflation, which jumped in July to the highest since January 2020.

Northeastern China, Beijing and Hebei province have seen heavy rainfall and floods since the typhoon made landfall in southern Fujian province.

Grain-producing Heilongjiang is the latest place hit by Doksuri, which has caused deaths, displaced thousands and put China's disaster-response systems to the test after swamping Beijing and nearby cities.

The region is bracing for more downpours two weeks after the Yamuna river burst its banks inundating parts of the capital.

Dengue rates are rising globally, with reported cases since 2000 up eight-fold to 4.2 million in 2022, WHO says.

Rainfall of up to 130mm is expected in central Hebei, southeast Beijing, southern Tianjin and other places until Saturday morning.

Rescue workers are having to trek in with their equipment for almost two hours to reach the landslide, some accompanied by sniffer dogs.

South Korea is at the peak of its summer monsoon season and there has been heavy rainfall for the last three days, triggering widespread flooding and landslides, and causing a major dam to overflow.