Four seasons are recognized by the Indian meteorological department. They are: (i) the cold weather (December-March); (ii) the hot weather (April-May); (iii) the rainy season (June-September), and (iv) the season of the retreating south-west monsoon (October-November).
There are four broad climatic region based on rainfall. Practically the whole of Assam and west coast of India lying at the foot of the Western Ghots and extended from the north of Mumbai to Thiruvanan-thapuram are areas of very heavy rainfall. In contrast to these, the Rajsthan desert extending to Kutchh, and the high Ladakh plateau of Kashmir extending westward to Gilgit are regions of low precipitation. In between these areas at the extreme ends of the rainfall range are two areas of moderately high and low rainfall respectively. The former consists of a broad belt in the eastern part of the peninsula merging northword with the north India plains and southwords with coastal plains. The latter comprises a belt extending from the Punjab plains across the Vindhya mountains into western part of the Deccon widening considerably in the Mysore plateau.