Typhoon Bopha, with central winds of 120 kilometre per hour (75 mph) and gusts of up to 150 kilometre per hour (93 mph), battered beach resorts and dive spots on Palawan island on Wednesday but it was weakening as it moved west.
Hardest hit was the southern island of Mindanao, where Bopha made landfall on Tuesday. It triggered landslides and floods along the coast and in farming and mining towns inland.
Interior Minister Manuel Roxas said 300 people were missing.
"Entire families were washed away," Roxas, who inspected the disaster zone, told reporters.
Most affected areas were cut off by destroyed roads and collapsed bridges and army search-and-rescue teams were being flown in by helicopter.
Power was cut and communications were down.
According to tallies provided by the military and disaster agency officials, 283 people were killed.
Thousands of people were in shelters and officials appealed for food, water and clothing. Dozens of domestic flights were suspended on Wednesday.
The governor of the worst-hit province, Compostela Valley, in Mindanao said waves of water and mud came crashing down mountains and swept through schools, town halls and clinics where huddled residents had sought shelter.
The death toll in the province stood at 160. In nearby Davao Oriental province, where Bopha made landfall, 110 people were killed.
"The waters came so suddenly and unexpectedly, and the winds were so fierce," the Compostela Valley governor, Arthur Uy, told Reuters by telephone.
He said irrigation reservoirs on top of mountains had given way sending large volumes of water down to the valleys. Torrential rain often triggers landslides down slopes stripped of their forest cover.
Damage to agriculture and infrastructure in the province was extensive, Uy said.
Corn farmer Jerry Pampusa, 42, and his pregnant wife were marooned in their hut but survived.
"We were very scared," Pampus said. "We felt we were on an island because there was water everywhere."
Another survivor, Francisco Alduiso, said dozens of women and children who had taken shelter in a village centre, had been swept away.
"We found some of the bodies about 10 km (6 miles) away," Alduisa told Reuters. The only building left standing in his village was the school.
Another survivor, Julius Julian Rebucas, said his mother and brother disappeared in a flash flood.
"I no longer have a family," a stunned Rebucas said.
An army commander said two dozen people had been pulled from the mud in one area and were being treated in hospital.
About 20 typhoons hit the Philippines every year, often causing death and destruction.
Almost exactly a year ago, Typhoon Washi killed 1,500 people in Mindanao.