Eastern Taiwan
Eastern Taiwan Geography & Climate
Geography
Eastern Taiwan is a long, narrow region squeezed between the Central Mountain Range and the Pacific, and it is where the island’s tectonics are most visible.
The collision zone
Taiwan exists because the Philippine Sea plate is colliding with the Eurasian, and the suture between them runs directly through this region along the East Rift Valley. The Coastal Range east of the valley is geologically part of the Philippine plate; the Central Range west of it is not. The two are converging at several centimetres a year, which makes this one of the fastest-rising and most seismically active places on earth.
Taroko
The gorge is cut through marble — limestone metamorphosed by heat and pressure — and is narrow and deep because the rock is being uplifted roughly as fast as the Liwu river can cut down through it. The result is near-vertical walls over a kilometre high in places.
The coast
North of Hualien the mountains meet the sea directly at the Qingshui Cliffs, dropping around eight hundred metres straight into deep water. South of it the coast is a narrow terrace beneath the Coastal Range, with raised marine terraces recording successive uplifts.
The rift valley
A flat-floored trough about 180 kilometres long and only a few kilometres wide, intensively farmed for rice and fed by hot springs along the fault.
Earthquakes
Major events are frequent: the April 2024 earthquake, magnitude 7.4 and centred off Hualien, was the island’s strongest in twenty-five years and caused deaths and extensive damage in Taroko.
Climate Patterns
Eastern Taiwan has a warm, humid climate with no cold season, and its defining feature is exposure — this coast faces the open Pacific and takes whatever arrives.
Temperatures
Hualien and Taitung run 29 to 33°C in summer and 18 to 22°C in winter, with the Tropic of Cancer crossing near Ruisui so the southern half is technically tropical. The rift valley is a few degrees cooler than the coast, and the mountains behind it are cooler again.
Winter is better than the north’s
The north-east monsoon that keeps Taipei grey from December to February loses much of its moisture over Yilan, so Hualien and especially Taitung are noticeably sunnier and drier in winter than the north. This is a real reason to come in January.
Typhoons
The east coast is Taiwan’s most exposed and takes storms first, usually between July and October. The consequences are more serious here than elsewhere because the terrain is steep and the infrastructure is a single road and a single railway — a landslide can cut the region in half. Taroko and the coastal highway close routinely, and rebuilding after a bad season can take months.
Foehn winds
Air descending the Central Range can produce sudden dramatic heating in the rift valley, and Taitung has recorded some of the island’s highest temperatures this way.
Earthquake weather, so to speak
Not climate, but the two hazards compound: rain falling on slopes fractured by a recent earthquake produces far more landslides than the same rain would otherwise.