Climate
The Köppen classification depends on average monthly values of temperature and precipitation. The most commonly used form of the Köppen classification has five primary types labeled A through E. These primary types are A) tropical, B) dry, C) mild mid-latitude, D) cold mid-latitude, and E) polar. The five primary classifications can be further divided into secondary classifications such as rainforest, monsoon, tropical savanna, humid subtropical, humid continental, oceanic climate, Mediterranean climate, desert, steppe, subarctic climate, tundra, and polar ice cap.
Trewartha climate classification
Climates with no more than two dry months (defined as having less than , average precipitation, same as per Köppen) are classified "Ar", while others are classified "Aw" if the dry season is at the time of low sun/short days or "As" if the dry season is at the time of high sun/long days. There was no specific monsoon climate identifier in the original scheme, but "Am" was added later, with the same parameters as Köppen's (except that at least three months, rather than one, must have less than 60 mm average precipitation).