Hong Kong is bracing for scorching heat before showers and thunderstorms return from Sunday amid a developing area of low pressure, according to the city’s weather forecaster.

The mercury may reach 33 degrees Celsius (91.4 degrees Fahrenheit) or higher on Friday and Saturday due to an anticyclone aloft affecting the coast of southern China over the next couple of days, before it starts to rain from Sunday, according to the nine-day weather forecast.

The Hong Kong Observatory said on Thursday that the coming unstable weather would be brought by a low-pressure area located east of the Philippines, which was expected to shift over Luzon the next day, and then traverse the central to northern South China Sea.

This system could intensify towards the southern areas of Hainan Island and its adjacent seas over the weekend, the forecaster added.

“Under the influence of the low-pressure system, there will be squally showers and thunderstorms over the northern part of the South China Sea and the coast of Guangdong during the weekend to early next week,” the Observatory said.