The deaths were reported in Khyber Pakhtunkhwa province during a downpour that began last night, a provincial disaster management agency spokesman said.
The number known to have died had now risen to 36, the spokesman said, adding reports were still awaited from a few more remote areas.
The worst-hit area was Kohistan where 12 deaths were reported, followed by Shangla district where rains and landslides killed 10 people.
Poorly-built homes, particularly in rural areas, are most susceptible to collapse during heavy spring rain.
During the rainy season last summer, torrential downpours and flooding killed 81 people and affected almost 300,000 people across the country.