The Hong Kong Observatory has warned residents to expect heavy showers and squally thunderstorms over the next few days.

“Showers will be heavier at times on Friday. There will be showers and thunderstorms over the weekend,” it said late on Wednesday.

The forecaster said the stormy weather in the region was related to a trough of low pressure that would affect Guangdong province persistently in the next few days.

“With the trough of low pressure moving away early next week, showers will ease off slightly over the region,” it said.

But it added that another trough of low pressure was expected to bring unsettled weather to southern China midweek next week.

The forecaster had warned at around 10pm on Wednesday that hail might affect Hong Kong in the next couple of hours, as an area of intense thundery showers to the west of the Pearl River Delta was gradually moving eastward.

Hailstones are large ice pellets formed in severe thunderstorms.

In the past few days, Hong Kong has been grappling with unstable weather, with the Observatory issuing multiple amber storm warnings due to heavy rain, which caused flooding in certain areas.

Hong Kong told to brace for more wet weather in week ahead

Hailstorms are relatively rare in Hong Kong, occurring about once every one or two years, according to the Observatory. Between January 2000 and August 2020, Hong Kong recorded 11 days with hail.

One notable event occurred on the evening of March 30, 2014, when a hailstorm was accompanied by widespread torrential downpours and severe thunderstorms amid a black rainstorm warning.

Numerous reports of hail were received from various areas, with most of them indicating the hailstones measured about 20mm (0.8 inches) to 30mm in size.

Hong Kong told to brace for more wet weather in week ahead

On March 25 last year, Hong Kong recorded an amber rainstorm warning accompanied by reports of hail in the Sai Wan Ho area. The Observatory issued four hail warnings between 12.30pm and 5.35pm that day, advising residents to seek shelter due to the intense thundery showers moving across the Pearl River Delta.

There were additional reports of hail on April 21 of the same year. Hail was also reported on September 16, 2021.

Since records began in 1967 until March 2023, Hong Kong has documented 41 occurrences of hail. It is most frequently observed in the months of April and March in the region.