Why the bulk of rainfall in India is concentrated over a few months?

The bulk of rainfall in India is concentrated over a few months beginning from June to September. During this period, the inflow of southwest monsoon into India brings about a total change in its weather. Early in the season, the windward side of the Western Ghats receives very heavy rainfall, more than 250 cm. The Deccan Plateau and parts of the Madhya Pradesh also receive some amount of rain in spite of lying in the rain shadow area. The maximum rainfall of this season is received in the
north-eastern part of the country. The distribution of rainfall received from the southwest monsoon is governed mainly by the relief of the country. So, the southwest monsoon is responsible for the concentration of rainfall over a few months.