Typhoon Doksuri has moved north in China after hitting Fujian province last week and before that wreaking havoc in the Philippines.
The heavy rains swept across the capital on Saturday with almost double the average rainfall for the entire month of July in just 40 hours.
On Tuesday, state broadcaster CCTV said the rain had killed at least 11 people in Beijing, with 13 people still missing.
In nearby Hebei province, where more than 800,000 people have been evacuated, nine people are reported dead and six are missing.
Two more fatalities were reported in Liaoning province over the weekend.