Relentless monsoon rains lashed Pakistan's most populous province overnight and on Thursday, killing 24 people and injuring 18, emergency services said.
Most of the deaths were caused by collapsing roofs and walls, according to the emergency services spokesman Muhammad Asghar.
Many homes in rural Pakistan are made of sun-baked mud and straw or flimsy cinder bloc construction, he said. Three men died when a landslide damaged a coalmine.
In the provincial capital of Lahore, the country's cultural hub with a population of nearly 13 million people, streets were flooded and homes in the poorest areas of the city were inundated with water.
Monsoon rains wreak havoc in cities and towns across Pakistan where drainage and sewage systems are antiquated and outdated.
Deadly floods occur regularly during the monsoon season in both Pakistan and neighboring India.