The northern Kaghan, Swat and Neelum valleys were the worst hit.
"For October, this has been the worst rainfall we have seen for at least 30 years," said Hazrat Mir, a senior official at the Pakistan Meteorological Department, according to Reuters.
In Kaghan Valley, home to about 100,000 people, one person was killed and 20 injured when their gemstone mining camp in the village of Baisar collapsed under the weight of snow, police said.
At least 3,000 tourists, mostly Pakistanis, were stranded in the town of Naran, also in Kaghan, said Abdullah Khan, a National Highway Authority official.
"We have been working all night with the army engineers and the local administration, and we have now opened the routes between Naran and Kaghan and the Babusar Pass, removing landslides from the road," he said.
Islamabad, in northern Punjab province, Sunday received 136 mm (5.35 inches) of rain, compared to the previous single-day record in October of 49.4 mm (1.94 inches).
Meteorologists have blamed the heavy rains on the El Nino weather pattern, and more rain is expected this week, Mir said.