Manila: The intertropical convergence zone (ITCZ) affecting southern Mindanao will bring rains across the island, the weather bureau said Monday. Davao Region, Surigao del Sur, Sarangani, Sultan Kudarat, Basilan, Sulu, and Tawi-Tawi will experience scattered rains and thunderstorms. According to Philippines News Agency, moderate to heavy rains in the aforementioned areas could result in flash floods or landslides, the Philippine Atmospheric, Geophysical and Astronomical Services Administration (PAGASA) said. Isolated rain showers or thunderstorms will prevail over the rest of Mindanao. Severe thunderstorms could also result in flash floods or landslides, PAGASA warned. The rest of the country will continue to experience isolated rain showers or thunderstorms due to the easterlies. Based on PAGASA's forecast heat index, 44 °C is expected in Dagupan City, Pangasinan and Aparri, Cagayan. A 43 °C heat index is forecast in Tuguegarao City, Cagayan; ISU Echague, Isabela; Cubi Pt., Subic Bay, Olongapo City; San Il defonso, Bulacan; and Sangley Point, Cavite City. The heat index could peak at 42 °C in NAIA; Bacnotan, La Union; Casiguran, Aurora; Ambulong, Tanauan Batangas; San Jose, Occidental Mindoro; Puerto Princesa City, Palawan; Daet, Camarines Norte; Masbate City; CBSUA-Pili, Camarines Sur; Dumangas, Iloilo; Catarman, Northern Samar; and Zamboanga City, Zobonga del Sur. Heat index is what the temperature feels like to the human body when relative humidity is combined with the air. Under danger level or 42°C to 51°C heat indices, heat cramps and heat exhaustion are likely. Continued exposure could also cause heatstroke. Meanwhile, light to moderate winds and slight to moderate seas will prevail across the archipelago, PAGASA said.