The worst affected is Thua Thien-Hue Province, where at least four people died, according to the Central Steering Committee on Natural Disaster Prevention and Control.
They included a 49-year-old teacher who was crushed by a falling tree while he was returning home last Friday as the storm made landfall over the central coast before weakening into a tropical depression. He died a day later.
Two other men, aged between 33 and 35, died while fixing their damaged houses after the storm.
On Friday a 47-year-old man was killed by a falling tree in Thua Thien-Hue’s Phong Dien District.
Ha Tinh and Quang Binh provinces have reported one death each.
Noul weakened by Friday morning after making landfall over Thua Thien-Hue and Quang Tri provinces with winds of up to 90 kph, bringing heavy rains and causing widespread power outages.
More than 280,000 families in Hue lived without electricity since Friday. As of Sunday many parts still did not have power, and over 10,000 trees have fallen.
In the ancient town of Hoi An in Quang Nam Province, heavy rains inundated many streets and caused erosion at Cua Dai Beach. The beach had been closed for three years as a result of erosion and only reopened in 2017.
In the tourist city of Da Nang, torrential downpours since Thursday morning triggered heavy flooding and inundated many houses in Thanh Khe District.
Noul is the fifth tropical storm this year in the East Sea, known internationally as the South China Sea. The fourth, Higos, made landfall in China last month.
The East Sea could see 11-13 storms and tropical depressions this year, half of them affecting Vietnam, meteorologists have warned.
Its long coastline makes Vietnam particularly prone to destructive storms and flooding. Natural disasters, predominantly floods and landslides triggered by storms, killed 132 people and injured 207 others last year.