Under the Köppen climate classification, the region is divided into 3 broad types: A (tropical climates), C (warm temperate mesothermal climates), and D (snow microthermal climates). The tropical climates are located in parts of Manipur, Tripura, Mizoram, and the Cachar plains south of 25oN and are classified as tropical wet and dry ("Aw").. Much of Assam, Nagaland, northern parts of Meghalaya and Manipur and parts of Arunachal Pradesh fall within the warm temperature mesothermal climates (type C) where the mean temperatures in coldest months are between . The entire Brahmaputra valley has a humid subtropical climate ("Cfa/Cwa") with hot summers. At altitudes between located in the eastern hills of Nagaland, Manipur and Arunachal Pradesh, a ("Cfb/CWb") climate prevails with warm summers. Locations above in Meghalaya, parts of Nagaland, and northern Arunachal Pradesh have a ("Cfc/Cwc") climates with short and cool summers. Finally, the extreme northern parts of Arunachal Pradesh have are classified as humid continental climates with mean winter temperatures below .