Why does monsoon blow northwards in summer and southwards in winter?

Monsoon winds blow northwards in summer due to the intense heating of the Indian subcontinent, which creates a low-pressure area that draws moist air from the Indian ocean. This results in the southwest monsoon bringing rainfall to the region. Conversely, in winter, the land cools rapidly, leading to the formation of high-pressure areas over the continent. Consequently, winds blow southwards from this high-pressure zone towards the lower pressure over the ocean, resulting in the northeast monsoon.