The city of Peshawar has been entirely cut off from the rest of the country, and the Pakistani military has sent boats and helicopters to surrounding areas to rescue stranded villagers.
Meanwhile, army engineers were working around the clock to divert floodwaters away from major roads so that rescue teams could reach stricken areas.
Rising death toll
Officials warn that the death toll is almost certain to rise, as many areas of the country are inaccessible.
"We have not collected the complete figures from some districts and fear the number of casualties is much higher," Anwer Kazmi, a spokesman for the Pakistani charity the Edhi Foundation, said.
Al Jazeera's Sohail Rahman, reporting from Pakistan's capital Islamabad, said that the government there was coordinating a response.
"They have managed to deploy three battalions of the military, both by air, on the water and by foot," he said. "We estimate there are 2400 personnel working to help the survivors of the flooding."
Sonia Cush, the Director of Emergency Response at Save the Children charity in Washington DC, told Al Jazeera they were able to help flood survivors because they were situated near the badly affected areas in Pakistan.
"We currently have emergency health teams moving around within the affected area treating people who urgently need healthcare, and our priorities are food, clean drinking water, healthcare and hygiene materials to ward off diseases.
"Our doctors have treated over 600 people just in the last two days and they are seeing a lot of cases of diarrhoea, fever and skin infections," Cush said.
"We will be distributing plastic sheeting to build makeshift shelters, but the hard work will only begin once the flood waters start to recede."
A UN situation report into the crisis said that many parts of the affected area have still not been reached.
"Search and rescue as well as assessments operations are still patchy and do not cover the whole of the affected area," the report said.
Mian Iftikhar Hussain, Khyber Pakhtoonkhwa's information minister said that a lack of suitable equipment was hampering rescue efforts.
"A rescue operation using helicopters cannot be conducted due to the bad weather, while there are only 48 rescue boats available for rescue," he said.
The floods came after what meteorologists described as an "unprecedented" 12 inches of rain fell in just 36 hours. Experts believe the worst of the rainfall is now over, but the extent of the damage is still being assessed.
Poor weather this week also may have been a factor in Wednesday's Airblue plane crash that killed 152 people near the Pakistani capital, Islamabad.