How do empirical climate classifications group regions?

Empirical climate classifications group regions by using observed environmental data, such as temperature, humidity, and precipitation, or simple quantities derived from these measurements, such as evaporation. Unlike genetic methods, which focus on the causal atmospheric processes behind climate patterns, empirical methods are primarily descriptive.1

A prominent approach within this category is the Köppen climate classification, which uses vegetation as a long-term integrator of a region's climate. Because natural vegetation responds to environmental conditions, it serves as a proxy for measuring climate in a manner similar to how a thermometer measures temperature. The Köppen system defines climatic boundaries based on formulas that correspond to mapped vegetation zones, utilizing temperature and precipitation criteria to categorize terrestrial climates into major types.23

Other empirical schemes may group regions based on different criteria, such as agricultural potential or the effects of climate on human comfort, which incorporates parameters like wind speed and solar radiation.3