Figure 12 – India: Normal dates of withdrawal of the Southwest Monsoon

3.8. Features of Monsoon Rainfall

♤ Monsoon rain is seasonal in character which occurs between June and September.

♤ Spatial distribution of rainfall is largely governed by relief or topography. For instance the windward side of the Western Ghats registers a rainfall of over 250 cm. Again, the heavy rainfall in the northeastern states can be attributed to their hill ranges and the Eastern Himalayas. Rainfall ranges from 20 cm in western Rajasthan to more than 400 cm in certain parts of Western Ghats and North-East India.

♤ The monsoon rainfall has a declining trend with increasing distance from the sea. Rainfall decreases from east to west in plains as one branch of monsoon enters from eastern side. Kolkata receives 119 cm, Allahabad 76 cm and Delhi 56 cm only.

♤ Breaks (discussed above) in rainfall are related to the cyclonic depressions mainly formed at the head of the Bay of Bengal, and their crossing into the mainland. Besides the frequency and intensity of these depressions, the passage followed by them determines the spatial distribution of rainfall.

♤ The rains sometimes end considerably earlier than usual, causing great damage to standing crops and making the sowing of winter crops difficult.