Large parts of Luzon and Visayas may experience floods in low-lying areas due to an inter-tropical convergence zone or band of clouds, the weather bureau said Tuesday.
The weather system will bring light to moderate rains over Metro Manila, Central Luzon, Calabarzon, Mimaropa, Bicol Region, and Visayas, said PAGASA meteorologist Chris Perez.
The rest of the country may experience occasional heavy rains brought by localized thunderstorms in the afternoon or evening, he added.
"Kapag ganitong panahon ng tag-ulan, 'pag wala po tayong bagyo at habagat, asahan na po natin itong mga ganitong thunderstorm," he told radio DZMM.
(During the rainy season, if we are not affected by any storm or the southwest monsoon, we should expect thunderstorms.)
PAGASA declared the start of this year's rainy season in the first week of June.
Visit the ABS-CBN Weather Center for the latest weather updates.