Dr. Prisco Nilo, acting PAGASA director, said there are also indications that El Niño would likely continue through April to June next year.
"El Niño indicators have strengthened in October, indicating progressive evolution of the current episode (of El Niño). This was manifested by a rise in sea surface temperatures in the Central Equatorial," he said.
PAGASA also observed a "consistently negative" Southern Oscillation Index which pertains to the difference in sea level pressure between Tahiti and Darwin, the stations near the centers of the two poles of the oscillation mass.
Nilo urged all concerned government agencies to implement measures to mitigate the possible impact of the water shortage on agriculture, hydropower generation, health and sanitation, among others.
The weather conditions that affected the country in October were the inter-tropical convergence zone (ITCZ), the tail-end of the cold front, the northeast monsoon, and typhoons "Ompong" and "Paeng."
Nilo added that rainfall last October was below to near normal in most parts of country, except in Isabela and Tarlac, which were hit by "Paeng," and the Zamboanga Peninsula, Davao del Sur, Cotabato, Maguindanao, Basilan and Sulu which were affected by the ITCZ.
"Rainfall in these areas was observed to be above normal. Temperature recorded in the country ranged as follows: 24oC to 32oC for the Visayas, 22oC to 33oC in the lowlands of Mindanao, and 20oC to 28oC in the mountainous areas of Mindanao," he said.
The weather systems that are expected to affect the country this November are still the northern monsoon, the tail-end of the cold front, the ITCZ, and one or two tropical cyclones.
PAGASA forecasts rainfall to be below normal in most parts of the country, except in Isabela, Quirino, Aurora, Region 4-B (Mimaropa), Region 5 (Bicol), Region 8, South Cotabato and Surigao where rainfall is expected to be normal.
PAGASA, according to Nilo, will continue to monitor the day-to-day weather situation and the large-scale climatic patterns affecting the Philippines, and will issue monthly updates on El Niño.