The densely populated Chinese capital of ‌Beijing braced for the expected onset of more than one-third of its annual rainfall over 24 ​hours starting late on Tuesday as ​moisture from Typhoon Dolphin to the south converged ⁠with cool air over northern China.

From ​Tuesday evening through Thursday, most areas in ​Beijing will experience heavy downpours with a cumulative rainfall of over 100mm in 6 hours and ​more than 150mm in 24 hours, ​according to the city’s meteorological service.

The cumulative rainfall in ‌districts ⁠including Tongzhou, Daxing, Fangshan, Mentougou, Huairou, and Fengtai may exceed 200mm in 24 hours.

That compares with Beijing’s average annual rainfall ​of 528 mm, the ⁠bulk of which is concentrated in the months between June ​and September.

In the mountainous district of ​Mentougou ⁠in western Beijing, authorities issued the highest level of flood emergency alert on Tuesday and ⁠advised ​people to stay indoors ​unless necessary and avoid travelling to mountainous areas and ​rivers.