Wladimir Köppen created the climate classification system first published in 1884 and later expanded worldwide.
Köppen was a German-Russian climatologist and meteorologist who organized climates using measurable patterns of temperature and precipitation, together with the distribution of vegetation. His original system appeared in 1884 and was revised several times as more observations became available.
The modern Köppen climate classification uses letter codes. Major groups include tropical, dry, temperate, continental, and polar climates. Subdivisions distinguish features such as dry seasons, hot summers, and cold winters. For example, Af denotes a tropical rainforest climate, while BWh identifies a hot desert climate.
Köppen’s system is widely used because it connects numerical climate data with recognizable environmental patterns. It is not a forecast model and does not describe every local microclimate. Köppen’s son-in-law, climatologist Rudolf Geiger, later helped revise the system, which is why it is often called the Köppen–Geiger classification.