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What does the w stand for in the Aw tropical climate code?
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Köppen climate classification
The major climatic types are based on patterns of average precipitation, average temperature, and natural vegetation. This map depicts the world distribution of climate types based on the classification originally invented by Wladimir Köppen in 1900.
In the Köppen climate classification system, the "w" in the Aw climate code stands for "winter dry season".1
Type A climates are the warmest climates and are differentiated based on the seasonality of their precipitation. While "f" denotes no dry season and "m" indicates a short dry season, the "w" designation specifically identifies the tropical wet-dry climate, which is characterized by a distinct dry season during the low-sun period.21