A climate zone is a region of the world where the climate can be defined using a few key parameters. There are a number of different ways to classify the world's climate zones, and a wide assortment of uses for this information. Gardeners, for example, rely on them to know which plants they can grow, while biologists use data about the zones to learn more about the animals and plants they study.
One of the most widely used systems is the Köppen climate classification, developed in the early 20th century by a German researcher. Köppen breaks the world's climate up into tropical, dry, moderate or temperate, continental, and polar climate zones. Within each division, there are a number of subdivisions, such as dry arid and dry semiarid. Some people break the world more generally into polar zones near the poles, followed by temperate zones, which meet a tropical zone at the equator. This division system is a bit of an oversimplification, however, and it overlooks the great diversity within these broad zones.
A number of pieces of data can be used to calculate a climate zone. Average temperatures, including average highs and lows, can be very useful, along with the average rainfall. Considerations like weather patterns, wind, and neighboring climates may also be considered. This allows the zones to be divided between things like tropical wet, with lots of humidity, wet weather year round, and tropical wet and dry, which has both wet and dry seasons.
Being able to identify a climate region can be very important. Some climates are more hospitable to farming, for example, while others may harbor unique plant and animal species which cannot thrive elsewhere. Identifying modern zones can also provide information about the shifting of the world's climate, by providing data that can be used to analyze ancient evidence, which can in turn be used to reconstruct the planet's historic climate.
Some examples of tropical climates in the Köppen system include the rain forests of South America, the island of Hawaii, and the savanna of India. Dry climates can be found in Egypt, the plains of Spain, and Australia, while temperate climates are distributed across regions like the West Coast of the United States, the coastline of the Mediterranean, and South Africa. Continental climates are found in places like China, Russia, and central Canada, while polar climates are seen in Antarctica, northern Russia, and northern Canada.