Climatic regions of India

India has a large variation in climate from region to region, due to its vast size. India experiences climate from four major climate groups. These can be further subdivided into seven climatic types. For ecological regions, see Ecoregions of India, for Regions see List of regions of India.

The regions belonging to this group experience persistent high temperatures which normally do not go below 18 °C even in the coolest month.

The west coastal lowlands, the Western Ghats, and southern parts of Assam have this climate type. It is characterised by high temperatures throughout the year, even in the hills. The rainfall here is seasonal, but heavy and is above 78 cm in a year. Most of the rain is received in the period from May to November, and is adequate for the growth of vegetation during the entire year. December to March are the dry months with very little rainfall. The heavy rain is responsible for the tropical wet forests in these regions, which consists of a large number of species of animals.Evergreen forests are the typical feature of the region.

Most of the plateau of peninsula India enjoys this climate, except a semi-arid tract to the east of the Western Ghats. Winter and early summer are long dry periods with temperature above 18 °C. Summer is very hot and the temperatures in the interior low level areas can go above 45 °C during May. The rainy season is from June to September and the annual rainfall is between 75 and 150 cm. Only central eastern Tamil Nadu falls under this tract and receives rainfall during the winter months of late November to January.

This group consists of regions where the rate of evaporation of water is higher than the rate of moisture received through precipitation.

A long stretch of land situated to the south of Tropic of Cancer and east of the western ghats and the Cardamom Hills experiences this climate. It includes Karnataka, interior and western Tamil Nadu, western Andhra Pradesh and central Maharashtra.This area receives minimal rainfall due to being situated in the rainshadow area. This region is a famine prone zone with very unreliable rainfall which varies between 40 and 75 cm annually. Towards the north of Krishna River the summer monsoon is responsible for most of the rainfall, while to the south of the river rainfall also occurs in the months of October and November. The coldest month is December but even in this month the temperature remains between 20 °C and 24 °C. The months of March to May are hot and dry with mean monthly temperatures of around 32 °C. The vegetation mostly comprises grasses with a few scattered trees due to the rainfall. Hence this area is not very well suited for permanent agriculture.

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