Koppen Climate Classification

The Koppen climate classification, developed by Wladimir Koppen in 1884, categorizes world climates into 5 main groups based on temperature and precipitation: A (Tropical), B (Arid), C (Temperate), D (Continental), E (Polar). Each is further subdivided by precipitation patterns (f: year-round wet, w: dry winter, s: dry summer).

Examples: Tokyo is Cfa (humid subtropical), Singapore is Af (tropical rainforest), Cairo is BWh (hot desert). This system correlates strongly with vegetation distribution.

In geography quizzes, climate clues like 'annual rainfall below 50mm' point to desert (BW) countries, while 'coldest month above 18C' indicates tropical (A) nations.