Typhoon Maysak's strength decreased to maximum sustained winds of 175 kilometres per hour (kph) and gusts of up to 210 kph as it moved towards the northern Philippines, the weather bureau said.
It is expected to make landfall on Saturday or Sunday over the eastern coast of the northern provinces of Aurora or Isabela.
"The typhoon could further weaken as it crosses land, but it will still bring rains and cause rough seas," said Esperanza Cayanan, head of the weather bureau.
Cayanan added that Maysak could generate tidal surges of up to 4metres, stressing that people living in coastal areas should be on alert.
The typhoon is due to hit the Philippines as millions of Filipinos goon holidays for the Holy Week, travelling to the provinces and hitting beach resorts.
Alexander Pama, head of the national disaster risk management council, said local government units have prepared for floods or landslides that might be caused by the typhoon.
"Once a storm warning is raised by the weather bureau, all ships and vessels will be stopped from sailing," he added.
The Philippines is hit by an average of 20 cyclones every year. Maysak is the third this year, but the first in decades to hit duringthe Easter holiday and at the start of summer.