Thick clouds, gusty winds, and persistent rainfall blanketed much of Luzon on Thursday, June 4, 2026, as the southwest monsoon — or habagat — tightened its grip over the northern and central parts of the country. The Philippine Atmospheric, Geophysical and Astronomical Services Administration (PAGASA) released its 4:00 AM weather bulletin, warning Filipinos in affected areas to stay vigilant against flash floods and landslides throughout the day and into the following morning.
The forecast remains in effect until 4:00 AM on Friday, June 5, 2026, covering the entire Philippine archipelago — though the most severe monsoon-related hazards are concentrated in Luzon, while the Visayas and Mindanao contend with a separate but still dangerous threat from localized thunderstorms.
Luzon Bears the Brunt of the Monsoon
The habagat is the dominant weather system driving conditions across Luzon on Thursday, and its effects span nearly the entire island group. While intensity varies by location, hazards are present in virtually every province.
Ilocos Region and Western Central Luzon
Among the hardest-hit areas are the Ilocos Region and the western Central Luzon provinces — specifically Zambales, Bataan, Tarlac, and Pampanga. These communities sit directly in the path of the monsoon's moisture-laden winds, and PAGASA has forecast occasional rainfall that may reach moderate to heavy intensity. The state weather bureau warns that such rainfall levels are sufficient to trigger flash floods in low-lying areas and landslides along unstable hillsides. People residing near riverbanks, drainage channels, or elevated terrain are urged to remain on high alert.
Metro Manila, CAR, CALABARZON, and the Broader Luzon Region
A wider band of Luzon — stretching from Metro Manila through Cagayan Valley, the Cordillera Administrative Region (CAR), CALABARZON, MIMAROPA, and the remaining provinces of Central Luzon — faces cloudy skies with scattered rains and thunderstorms, according to PAGASA's bulletin.
Rainfall in these areas may intensify at times, heightening the risk of flash floods and landslides. Millions of commuters in Metro Manila and its neighboring provinces can expect sudden downpours, reduced visibility, and flooded roads during peak travel hours. The mountain provinces of CAR — among them Benguet, Mountain Province, Ifugao, Kalinga, Abra, Apayao, and Baguio City — face a particularly elevated landslide risk given the steep and often already-saturated terrain in those highlands.
"Possible flash floods or landslides due to moderate to at times heavy rains." — PAGASA, 4:00 AM Weather Forecast, June 4, 2026
Visayas and Mindanao: Thunderstorms Still Pose Risks
Across the Visayas and Mindanao island groups, as well as portions of Southern Luzon not directly influenced by the monsoon, conditions on Thursday will be partly cloudy to cloudy with isolated rain showers and thunderstorms. These weather systems are driven by localized convective activity rather than the habagat itself.
Although the situation may appear comparatively calmer in these regions, PAGASA emphasizes that isolated severe thunderstorms remain capable of producing flash floods and landslides. Residents living near rivers, creeks, or mountainous terrain across Eastern Visayas, Western Visayas, Central Visayas, Zamboanga Peninsula, Northern Mindanao, Davao Region, SOCCSKSARGEN, Caraga, and the Bangsamoro Autonomous Region in Muslim Mindanao (BARMM) should monitor conditions closely — particularly during afternoon and evening hours when convective activity tends to peak.
Localized thunderstorms deserve special attention because they can unleash intense, concentrated rainfall over a narrow area in a matter of minutes, quickly overwhelming drainage systems and waterways even as surrounding localities stay dry.
Strong Winds and Rough Seas Along Western Luzon
Beyond the rainfall, the southwest monsoon is generating significant wind and wave activity along the western coastline of the Philippines. PAGASA reports that Northern Luzon, Central Luzon, and the western portions of Southern Luzon will experience moderate to strong southwesterly winds. Coastal waters in these zones are classified as moderate to rough, with wave heights ranging from 1.2 to 3.1 meters.
These conditions present genuine hazards for small watercraft. Fisherfolk and mariners working the waters off Ilocos Norte, Ilocos Sur, La Union, Pangasinan, Zambales, and Bataan — and across the West Philippine Sea — are strongly advised by PAGASA to either exercise extreme caution or delay their voyages until the sea state improves.
Elsewhere in the archipelago, winds will be lighter — blowing from the south to southwest at moderate speeds — and coastal waters are expected to be slight to moderate, with wave heights of 0.6 to 1.5 meters. While conditions are generally manageable for most vessels, small bancas should still observe standard maritime precautions.
Warm and Muggy Temperatures in Metro Manila
Despite the overcast skies and persistent rain, Metro Manila remains warm and uncomfortably humid. PAGASA's weather station at Science Garden in Diliman, Quezon City recorded a maximum temperature of 31.5°C at noon and a minimum of 25.3°C at 6:00 AM for the 24-hour period ending at 8:00 PM on June 3, 2026. Relative humidity fluctuated between 64% and 95%, consistent with the moist air mass being pushed inland by the habagat. Residents should prepare for a sticky, muggy feel throughout the day, even during brief pauses in the rainfall.
Tidal and Astronomical Data for Metro Manila
According to tidal predictions from the National Mapping and Resource Information Authority (NAMRIA), Metro Manila will experience a high tide of 1.23 meters at 11:42 AM and a low tide of -0.12 meters at 8:41 PM on Thursday. Sunrise is at 5:26 AM and sunset at 6:23 PM. The moon is at 85% illumination, with moonrise at 9:41 PM and moonset at 8:21 AM.
Safety Guidelines for June 4
PAGASA's bulletin contains explicit hazard warnings that all Filipinos should take seriously, regardless of which island group they live in. Flash floods can develop within minutes of a heavy downpour in low-lying and flood-prone communities. Landslides remain a persistent threat in hilly and mountainous areas, especially where soil saturation from previous rains has already weakened the ground.
The following safety measures are strongly recommended:
Stay updated: Check PAGASA's latest advisories regularly throughout the day. Local government units (LGUs) may issue their own supplemental warnings as conditions evolve.
Stay away from floodwaters: Never attempt to cross flooded roads or swollen waterways, even when the water appears shallow. Fast-moving floodwater can knock down adults and sweep away vehicles.
Follow evacuation orders immediately: If local authorities direct residents — particularly in landslide-prone barangays within Luzon's mountain provinces — to evacuate, do so without delay and do not wait for visible signs of danger.
Mariners and fisherfolk: Those along the western coast of Luzon should avoid venturing into rough seas. Wave heights of up to 3.1 meters can capsize small fishing boats without warning.
Motorists and daily commuters: Anticipate reduced road visibility during thunderstorms and the likelihood of flooded underpasses and streets in Metro Manila and other urban centers. Allot extra travel time and avoid roads with a history of flooding.
The 24-hour public weather forecast issued by PAGASA at 4:00 AM on June 4, 2026 is valid until 4:00 AM on June 5, 2026. The agency will issue updates as conditions change. The public is encouraged to monitor the official PAGASA website at pagasa.dost.gov.ph for the most current information.
Source: breakingnewsnegor.com