Subtropical describes the belt of the world that lies just outside the tropics — warm most of the year, but with a real winter, or at least a cooler season. Geographers usually put it roughly between 23.5° and 40° north or south. Northern Taiwan is subtropical; the south of the island, below the Tropic of Cancer that runs near Chiayi, is tropical. So this is a word Taiwanese students meet in their own geography lessons before they meet it in English.

It is used of climates, of regions, and of the plants and animals that belong there: a subtropical climate, subtropical fruit, a subtropical forest. The feeling it gives is humid heat with a break — hot sticky summers, mild but not freezing winters.

Be aware that people stretch it. In everyday speech and especially in travel writing and property advertising, "subtropical" often just means "pleasantly warm and a bit exotic," with no real thought about latitude at all. A hotel in a place that is not subtropical by any scientist's measure may still describe its garden as subtropical because it has palm trees. Scientists themselves also disagree about exactly where the boundaries fall, so even the technical use has soft edges.