Nearly 25,000 people were also displaced by floods and landslides amid days of continuous torrential rains since last week, the national disaster agency said.

A 39-year-old woman died on Friday in the northern city of Bagiuo when a tree fell and crushed a taxi she was riding in, the agency said on Sunday.

Two people were also injured in the accident.

In the northern province of Ilocos Norte, a 35-year-old farmer and a 15-year-old boy were killed when they were struck by lightning, police said. Three people were also injured in the lightning strike.

Mark Timbal, a spokesman for the national disaster agency, said 87,493 people have been affected by the bad weather since last week when typhoon In-Fa swept through the northern Philippines.

While In-Fa did not make landfall, it enhanced the southwest monsoon that brought rains over northern provinces and the capital region of Metro Manila.

Timbal said they were hoping the weather would improve next week but that the national disaster agency has issued a reminder that even once the typhoon is gone, there would still be a monsoon.

"So let us not be complacent," Timbal said over Manila radio station DZMM.

In-Fa was packing maximum sustained winds of 140km/h and gusts of up to 170 km/h as it moved out of the Philippines on Saturday, according to the weather bureau.

The bureau warned of scattered to widespread flooding and rain-induced landslides due to the monsoon rains.

Australian Associated Press