The death toll from Typhoon Kompasu has risen to 19 after a month’s worth of rain fell in the Philippines in just two days.
Kompasu triggered landslides and flash floods across the archipelago, with authorities blaming “a new normal caused by climate change”.
National disaster agency spokesman Mark Timbal said the rainfall was "even greater” than from Typhoon Ketsana, which was categorised in the Philippines as Tropical Storm Ondoy, which hit in 2009 and claimed hundreds of lives.
Kompasu, named after the Japanese pronunciation of compass, intensified the south-west monsoon that had already saturated areas of the disaster-prone country.
Provinces on the most populous island of Luzon were hit hardest by the storm, which caused damage worth an estimated $20 million-plus to the agriculture sector and damaged hundreds of homes.
"This only proves the effect of climate change when it comes to the increasing magnitude of these natural hazards," Mr Timbal said. "This continues to pose a challenge to our disaster management system. We always have to step up our preparations in view of the worst-case scenario for every natural hazard."
Because a warmer atmosphere holds more water, climate change increases the risk and intensity of flooding from extreme rainfall.
The majority of the deaths were in the north-west province of Ilocos Sur, where most of the victims were caught in flash floods. The disaster agency is also checking another 11 reported fatalities, mostly in the landlocked mountainous province of Benguet. There are 14 people reported missing.
Mr Timbal said the "changing nature" of the hazards made it difficult for authorities to achieve their target of zero casualties. "Each hazard is unique to the next one," he said. "It's a new normal caused by climate change."
Mr Timbal said nearly 15,000 people fled their homes, but only about half stayed in evacuation centres. The rest sought shelter with friends or relatives because of fears of catching the coronavirus.
The storm moved across the South China Sea on Tuesday towards Hong Kong, forcing the international business centre to batten down.
The Philippines, ranked as one of the countries most vulnerable to the impacts of a warming planet, is hit by an average of 20 storms and typhoons every year, which typically wipe out harvests, homes and infrastructure in already impoverished areas.