Updated world map of the Köppen-Geiger climate classification

TLDR

The Köppen‑Geiger climate classification remains widely used in education and research for regionalizing climate variables and evaluating global climate model outputs. This study presents an updated global Köppen‑Geiger climate map derived from extensive long‑term precipitation and temperature station data and examines classification challenges across continents. Climatic variables were calculated at each station and interpolated onto a 0.1°×0.1° grid using a two‑dimensional thin‑plate spline with tension. The updated map shows hot desert (BWh) as the most extensive land climate at 14.2%, followed by tropical savannah (Aw) at 11.5%, and is freely available online. Abstract.

Abstract

Abstract. Although now over 100 years old, the classification of climate originally formulated by Wladimir Köppen and modified by his collaborators and successors, is still in widespread use. It is widely used in teaching school and undergraduate courses on climate. It is also still in regular use by researchers across a range of disciplines as a basis for climatic regionalisation of variables and for assessing the output of global climate models. Here we have produced a new global map of climate using the Köppen-Geiger system based on a large global data set of long-term monthly precipitation and temperature station time series. Climatic variables used in the Köppen-Geiger system were calculated at each station and interpolated between stations using a two-dimensional (latitude and longitude) thin-plate spline with tension onto a 0.1°×0.1° grid for each continent. We discuss some problems in dealing with sites that are not uniquely classified into one climate type by the Köppen-Geiger system and assess the outcomes on a continent by continent basis. Globally the most common climate type by land area is BWh (14.2%, Hot desert) followed by Aw (11.5%, Tropical savannah). The updated world Köppen-Geiger climate map is freely available electronically at https://www.hydrol-earth-syst-sci.net/????.