The vast territory of China spans nearly 50 latitudinal degrees and most of it is in the temperate zone, with a small part extending south into the tropical and subtropical zones and the northernmost tip close to the Frigid Zone. There are perennial icy and snowy zones in some alpine regions. China is a world-renowned monsoon region, where most parts are cold and dry in winter and hot and rainy in summer. Diverse temperature belts and arid and humid areas have formed the country’s complex climate, a complexity that is enhanced by the country’s variegated landform. The northern part of Heilongjiang Province has long winter but no summer, while the Hainan Island has long summer but not winter. The Huai River valley is marked by distinct seasonal changes, but it is spring all year round in the south Yunnan-Guizhou Plateau. In the Northwest hinterland, the temperature changes strikingly. China’s high tundra zone is in the southwest of the Qinghai-Tibet Plateau, where the temperature is low all year round. Some deserts are perennially dry and rain-poor.