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.
Environment of India
The climate comprises a wide range of weather conditions across a vast geographic scale and varied topography, making generalisations difficult. Given the size of India with the Himalayas, Arabian Sea, Bay of Bengal and the Indian Ocean, there is a great variation in temperature and precipitation distribution in the subcontinent. Based on the Köppen system, where the mean monthly temperature, mean monthly rainfall and mean annual rainfall are considered, India hosts six major climatic subtypes, ranging from arid desert in the west, alpine tundra and glaciers in the north, and humid tropical regions supporting rainforests in the southwest and the island territories. Many regions have starkly different microclimates. The Indian Meteorological Department divides the seasons into four: Winter (mid-December to mid-March), Summer (mid-March to May), Rainy (June to September), and Retreating Monsoon (October to mid-December).