Manila
Manila Geography & Climate
Geography
Manila occupies flat delta ground where the Pasig river enters Manila Bay, on the island of Luzon.
Bay and river
Manila Bay is a large natural harbour some 60 kilometres across at its widest, almost enclosed by peninsulas, which is why every colonial power wanted it. The Pasig runs 25 kilometres from Laguna de Bay, the largest lake in the country, through the middle of the city to the bay, dividing it north and south. It was the city’s highway for centuries and became biologically dead through the twentieth century; a long rehabilitation has brought some life back.
Low and sinking
Much of Metro Manila sits only a few metres above sea level on soft delta deposits, and groundwater extraction has caused parts of the northern and western fringes to subside by several centimetres a year — far faster than sea level is rising. Flooding is consequently chronic.
Density
The City of Manila proper packs over 1.8 million people into 43 square kilometres, which makes it among the most densely populated cities anywhere; the wider metropolitan area holds more than 13 million.
The West Valley fault
Runs through the eastern part of the metropolis and is capable of a major earthquake; planning scenarios for it are sobering and widely published.
Metro Manila
The capital is not one city but sixteen, plus a municipality, fused into a single built-up area of over 13 million people with no gaps between them. Manila proper is only a small part of it, and Makati, Quezon City and Taguig are separate cities with their own governments — which is why the metropolis has no single mayor and why coordinating anything across it, from traffic to flood control, is so difficult.
Reclamation
Large areas along the bay are made ground, with more proposed and contested.
Climate Patterns
Manila has a tropical savanna climate, which here means hot every day and a sharp division between dry and wet halves of the year.
Temperature
Warm to hot throughout, with highs from 30°C in January to 35°C in April and May and nights rarely below 24°C. Humidity is high all year and the heat index in April frequently exceeds 40°C, which is when the city is at its most punishing.
The dry season
December to May, with the amihan north-east monsoon bringing the coolest and most pleasant conditions from December to February, followed by the hot dry months of March, April and May when it barely rains at all.
The wet season
June to November, driven by the habagat south-west monsoon. Around 2,000 millimetres a year falls almost entirely in this period, in intense afternoon and evening downpours. Streets flood within minutes, and a serious storm can put whole districts under water and stop the city entirely.
Typhoons
The Philippines is struck by around twenty tropical cyclones a year, more than any other country, and several pass close enough to Manila to bring flooding and shut schools, offices and flights. The season runs June to November and peaks from August to October.
Habagat rains
The most damaging flooding often comes not from a typhoon hitting the city but from an enhanced south-west monsoon, when a storm passing well to the north drags a continuous stream of moisture over Luzon for days. Those events have put a third of the metropolis under water more than once.
Practical effect
Plan around the heat and the afternoon rain; malls and museums are the middle-of-the-day strategy.