At least 18 people have died in weather-related incidents since the rain started last week, including three were to killed in the past day, Pakistani media reported.
Heavy monsoon rains lashed Pakistan on Wednesday, causing deaths, flooding roads and disrupting lives in areas where residents already were struggling to recover from floods last summer that affected 33 million people and killed 1,739, officials said.
At least 18 people have died in weather-related incidents since the rain started last week, including three were to killed in the past day, Pakistani media reported.
The monsoon season officially started this week and will continue until September in the South Asian country. The first spell of rainy weather was expected to last until Saturday.
Pakistan's cultural capital, Lahore, received a record 272 millimetres (10.7 inches) of rain in nine hours Wednesday, flooding streets and the city's canal.
Efforts were underway to clear the water, Mohsin Naqvi, the top government official in Punjab province, said.
The last time Lahore received such a deluge was 30 years ago, officials said. Pakistan's capital, Islamabad, also had a heavy downpour this week.
The National Disaster Management Authority warned local authorities to prepare for emergencies such as flooding and landslides.
Last summer's devastating floods caused $30 billion in damage in cash-strapped Pakistan.