The Pakistan Meteorological Department (PMD) predicted moderate to heavy rains for Karachi from next week.
A low-pressure system in the Bay of Bengal may affect the city from September 7 to 11, said the Met office.
The department said that there is also a risk of urban flooding in the event of heavy rain in the city.
The PMD also said that there was no chance of heavy rain in the port city until September 5.