Question

Why are north east winds dry and south west winds carry a lot of rainfall?

Answer 1

South western winds carry a lot of rainfall because they become cold while travelling over the Indian Ocean. By the time they reach Indian sub continent, Condensation occurs in the atmosphere then droplets become heavy enough to fall under gravity.

This doesn't happen with north eastern winds because there is no ocean in the norther east part of India. Thus, When they reach India they become dry.

Answer 2

This complete reversal of wind direction from North-East to South West and vice-versa is known as monsoons. The windscontain a lot of moisture. When these moisture laden winds move over the Indian sub-continent they cause wide spread rainthroughout India and from June to September