On Tuesday, state broadcaster CCTV said the rains had killed at least 11 people in Beijing, two of whom were workers “killed on duty during rescue and relief” operations.
Thirteen people were still missing, but another 14 had been found safe, the broadcaster said.
In neighbouring Hebei province, where more than 800,000 people were evacuated, nine people were killed and six were missing, it said.
Another two casualties were reported in northeastern Liaoning province over the weekend.
President Xi Jinping on Tuesday called for “every effort” to rescue those “lost or trapped” by the rains.
China has been experiencing extreme weather and posting record temperatures this summer, events that scientists say are being exacerbated by climate change.
The country is now on alert for the arrival of typhoon Khanun, the sixth such storm of the year, as it nears China’s east coast.