Taiwan Outlying Islands
Taiwan Outlying Islands Geography & Climate
Geography
Taiwan’s outlying islands are geologically unrelated to each other and to the main island, which is why they look so different.
Penghu
Around ninety islands in the Taiwan Strait, formed by basalt lava flows that cooled into hexagonal columns, exposed now as cliffs and sea stacks at Daguoye, Tongpan and Xiyu. The islands are low — almost nothing above eighty metres — almost treeless because of the wind, and ringed by coral reef. Only about twenty are inhabited.
Kinmen
A granite island of about 150 square kilometres lying only two kilometres off the Chinese port of Xiamen and 187 kilometres from Taiwan. Low, undulating, and heavily wooded now as a result of a deliberate military afforestation programme to provide cover.
Matsu
A scatter of steep granite islands off the Fujian coast at the mouth of the Min river, with almost no flat ground, which is why the villages climb the hillsides.
Green and Orchid Islands
Both are volcanic, lying off Taiwan’s south-east coast in the Pacific, part of the same island arc as the Philippine chain. Green Island has uplifted coral terraces and one of the world’s few saltwater hot springs. Orchid Island is larger, steeper and wetter, with forested peaks above 500 metres.
How close is close
The distances are worth stating because they explain the politics. Kinmen sits about two kilometres from the Chinese coast at its nearest point — close enough that Xiamen’s skyline is the view from the beach, and close enough that swimmers have crossed it. Taiwan proper is 187 kilometres away. Matsu is similarly a few kilometres off Fujian and 190 from Taiwan. Both are administered from Taipei purely because of where the front line stopped in 1949.
Reefs and currents
The Kuroshio current runs past the eastern islands, bringing warm water and exceptional visibility for diving.
Climate Patterns
The outlying islands share a subtropical maritime climate, but the wind makes them very different places at different times of year.
The winter monsoon
This is the defining fact for Penghu and Matsu. From October to March the north-east monsoon funnels down the Taiwan Strait and blows relentlessly — Penghu records some of the highest average wind speeds of any inhabited place in the region, gales are routine, and salt spray carries far inland. It is why the islands are treeless, why fields have stone windbreaks, and why ferries are cancelled for days at a time. Much of the tourist economy simply closes.
Summer
May to September is warm to hot, 28 to 32°C, with calm seas in early summer and the islands at their best. This is also when Taiwanese visit in numbers.
Typhoons
From July to October. The eastern islands — Green and Orchid — are particularly exposed, and a storm can cut them off for the better part of a week, with ferries suspended and flights grounded.
Fog on Matsu
From March to May, dense sea fog closes Matsu’s airports frequently, sometimes for several consecutive days. Anyone flying there in spring should build in slack, and the ferry is the backup.
Planning around the wind
The practical consequence is that these islands have a genuinely short season. Penghu and Matsu are April to October propositions and are half-shut outside that; Green and Orchid Islands are best from March to June, before the typhoons and after the winter swell. A winter trip to Penghu is possible and the islands are atmospheric in the wind, but expect cancelled ferries, closed restaurants and very few other visitors.
Rainfall
Penghu is dry, around a thousand millimetres a year and with chronic water shortages; Orchid Island, mountainous and in the Pacific, is far wetter.