Heavy rain occurred in Lahore late on Wednesday and continued intermittently till Thursday, deluging roads and streets of the city.
Eight people were killed in two separate incidents of roof collapse in Lahore.
The overnight downpours submerged low-lying areas of Lahore including Wasanpura, Garhi Shahu, Garden Town, Ferozpur Road, Mall Road, Gulberg and Iqbal Town.
Rain/thunderstorm also lashed other cities of Punjab, including Sialkot, Gujranwala, Narowal, Kamoni, Gujranwala, Faisalabad and Sahiwal where roof collapse incidents and electrocution killed nearly a dozen people.
According to Pakistan Meteorological Department (PMD), at least 123mm precipitation was recorded in Lahore and its adjoining areas during last 12 hours.
It said the rainfall is likely to continue for next two to three days.
Rain emergency has been declared in the province as local administration has been put on high alert to kick off rescue efforts and prevent rain-related casualties.