Forecasters said, however, that Typhoon Halong was too far off at sea to hit the country directly.
The rains have flooded several farming villages in the north and caused traffic jams in the capital, Manila. A tugboat sank in rough seas over the weekend off Batangas province, south of Manila, and its three crewmen were rescued by the coast guard.
Government forecasters said Halong packed sustained winds of 165 kilometres per hour and gusts up to 200 kph. It was moving over the Pacific about 840 kilometres east of northern Cagayan province and was forecast to blow towards southern Japan this week.
Forecaster Gladys Saludes said Halong, the 10th of about 20 tropical storms and typhoons expected to batter the Philippines this year, will blow out of the country Thursday.