Movement of air or wind is a result of pressure difference between two places. Wind always blows from high to low pressure. The pressure gradient is in turn created by temperature changes.The weather at a place is decided by change of conditions in the lower atmosphere like temperature, rainfall, humidity, wind etc
Winds are the result of the motion of air molecules.
a. During winter, there is a high-pressure area north of the Himalayas. Cold dry winds blow from this region to the low pressure areas over the oceans to the south.
b. In summer, a low-pressure area develops over interior Asia as well as over northwestern India.Air moves from the high-pressure area over the southern Indian Ocean, in a south-easterly direction, crosses the equator, and turns right towards the low-pressure areas over the Indian subcontinent, which acuses rainfall over the mainland India.