Hong Kong matched on Friday its record for the hottest summer solstice as a subtropical ridge drove temperatures up to 34 degrees Celsius (93.2 degrees Fahrenheit).

"The maximum temperature recorded at the observatory was 34C, the highest so far this year and equalling the record high for summer solstice set in 1980," the city's weather observatory said.

The Chinese finance hub saw its hottest summer on record last year, with the mean temperature hitting 29.7C (85F) in August.

The top three warmest years in Hong Kong's history were all recorded after 2018.

Scientists warn extreme heat globally will become more frequent and intense because of human-induced climate change.

The Observatory issued its "very hot weather" warning on Friday and health officials urged the public to drink plenty of water and take measures to avoid heatstroke.

Authorities said they will continue to operate 19 temporary heat shelters for people to spend the night.

Hong Kong has in recent years emphasised the need to protect workers from heat stress, but has stopped short of enacting legal safeguards.

The city does not list heatstroke as a work-related injury in its laws, and activists say government statistics undercount the number of workers who died of the illness.