koppen

Koppen, more commonly spelled Köppen, refers to the Köppen climate classification system, a widely used framework for categorizing the world’s climates. It was developed by the Baltic German climatologist Wladimir Köppen in the late 19th and early 20th centuries and refined by Rudolf Geiger in 1961, leading to the Köppen–Geiger classification that remains influential in modern climatology. The system classifies climates primarily by average monthly temperature and precipitation, linking climate types to patterns of vegetation and ecosystem behavior.

The Köppen system groups climates into five major classes: A tropical, B dry, C temperate, D continental, and E polar. Each major class has subtypes indicated by additional letters that describe precipitation regimes or winter conditions. For example, tropical climates have consistent warmth year-round; arid climates are defined by limited precipitation; temperate and continental climates have distinct seasonal patterns; polar climates are characterized by very cold temperatures. The letters form combinations such as Af (tropical rainforest), Am (tropical monsoon), Aw (tropical savanna), and the various C, D, and E subtype designations.

Applications of the Köppen–Geiger scheme include climate mapping, biogeography, agricultural planning, and ecological research. While it provides a practical and intuitive framework, it is a coarse categorization that abstracts away local variations, microclimates, elevation effects, and short-term variability. Nevertheless, it remains a foundational tool in climate education and in the creation of global climate datasets.