Köppen

Köppen most commonly refers to Wladimir Köppen, a German-Russian climatologist who devised the Köppen climate classification, one of the most widely used systems for describing Earth's climates. The classification links climate with vegetation by grouping climates according to typical temperature and precipitation patterns.

The system organizes climates into five principal groups: A tropical, B dry, C temperate, D cold, and E polar. Each group is subdivided using second letters that denote precipitation patterns and seasonality (for example Af tropical rainforest, Am tropical monsoon, Aw tropical savanna; BWh, BWk dry deserts; Cfa, Cwa warm temperate with wet summers; Dfa, Dfb cold temperate; ET tundra). The letters form many commonly cited climate types such as Af, Cfa, Dfb, and ET.

The original framework was introduced by Köppen in the early 20th century and was later revised and expanded by Rudolf Geiger, resulting in the Köppen-Geiger climate classification, which remains a standard in climatology and biogeography. The scheme is widely used for global climate mapping, ecological and agricultural planning, and as a basis for understanding patterns of vegetation and human activity.

Limitations include reliance on historical climate normals, simplified thresholds, and reduced accuracy for local microclimates. Despite these limitations, the Köppen system remains a foundational reference in climate science and is widely cited in textbooks and climate datasets.