South West Monsoon:(June to September) After the summer season, rainy season starts with the onset of south west monsoon. The high temperature gives rise to low pressure and by the end of May a large area of low pressure is formed over the north west part of the country.
North East Monsoon(October to November): The landmass of India starts losing heat and there is a fall in the temperature. But the sea is still in warm condition. High pressure develops over the land and low pressure over the sea.
Therefore wind blows from high pressure to low pressure that is from land to sea. It is cold dry wind and gives no rainfall to land mass. But when it crosses the Bay of Bengal, it absorbs moisture and gives heavy rain to the coromandal coast.