‘Siyam-Siyam’ in Luzon, Dangerous Heat in Mindanao: August Brings Weather Extremes to PH

(SPOT.ph) While Luzon has been dealing with days of heavy rain, parts of Mindanao are experiencing the exact opposite: dangerous heat. The extreme temperatures have prompted class suspensions in several areas as heat index forecasts reach at least 40°C. How can one part of the country be getting soaked while another is sweltering?

We know the southwest monsoon, or habagat, has brought rains across Luzon, worsening already stormy conditions from Tropical Depression Luis and Tropical Storm Maymay, with Typhoon Dolphin further enhancing the monsoon over the past few weeks. But its effects aren’t spread evenly across the Philippines, leaving parts of Mindanao with less rain and higher temperatures.

As El Niño raises temperatures in the central and eastern Pacific Ocean, it not only brings dry conditions but also warms the oceans. The Philippine Atmospheric, Geophysical and Astronomical Services Administration (PAGASA) said that when El Niño occurs during habagat season, it enhances the monsoon and brings more rain. This ultimately leads to varied weather conditions across the country.

Also read: When Will the Rain Stop in Metro Manila?

Metro Manila has hit what our elders call “siyam-siyam” or nine consecutive days and nine consecutive nights of rain. PAGASA said the continuous rains began around August 4 and persisted through the following week. According to meteorologist Ariel Rojas, nearly 400 millimeters of rain fell over parts of Metro Manila from August 5 to 10, equivalent to almost two months’ worth of rainfall at some PAGASA stations.

Traditionally, farmers waited for this “siyam-siyam” downpour as it signaled the beginning of the rainy season, meaning soil would be soft enough for planting.

But overly soft soil leads to landslides and muddy roads. Several roads remain impassable to traffic and at least 26 people have died from the combined effects of Luis, Maymay and the enhanced habagat, including 16 landslide fatalities in Benguet.

Luzon is no stranger to weathering storms. In July 1972, the rapid succession of Typhoon Edeng, Super Typhoon Gloring, Typhoons Huaning, Isang, and Konsing enhanced monsoon conditions from Northern to Central Luzon and Metro Manila. It's reported that over 600 people died in the “Great Luzon Flood,” with the damage amounting to P2 billion.

Also read: What PAGASA's Yellow, Orange, and Red Rainfall Warnings Mean

But it hasn’t been rainy days for all Pinoys.

PAGASA has previously warned that Central Visayas could see below-normal rainfall as El Niño intensifies over the coming months. There is a 97% chance it will persist until the first half of 2027. Meanwhile, Eastern and Western Visayas are expected to see near- and above-normal rains during habagat.

The conditions could be disastrous for farm output, which fell in the first quarter of 2026 due in part to the lingering effects of extreme weather.

At the other end of the spectrum, Mindanaoans are experiencing dangerous heat in the low 40°C range. Classes in Zamboanga del Norte, Davao de Oro, Cagayan de Oro City, and Misamis Oriental have been suspended to protect students from the risks of prolonged exposure to high temperatures.

From August 14 to 15, the Mindanao PAGASA Regional Services forecast a heat index of 46°C in Surigao City.

PAGASA classifies a heat index of 42°C to 51°C as dangerous. Heat cramps and heat exhaustion are possible at this level, while prolonged exposure may result in heat stroke.

Wherever you are, make sure to stay safe, stay indoors, and stay updated on the latest weather reports in your area.