Monsoon climate has developed in the Indian sub-continent because-

1. The Indian Ocean spreads between Africa in the west, Asia in the north and east, Australia in the east and Southern Ocean in the south. 

2. The Indian Ocean does not extend northwards to the Arctic Ocean like the Atlantic Ocean and the Pacific Ocean.

3. This has resulted in complete blockage of the Indian Ocean towards its north. 

4. This peculiar arrangement of the ocean and the continental portion contributes a lot to the development of the monsoon climate of the Indian subcontinent. 

5. During summer solstice, sun shines vertically on tropic of cancer, so there is summer season over the Indian subcontinent. 

6. Due to continuous heating, low pressure area is created, moisture laden south west monsoon winds give rainfall on the Indian sub-continent, that is rainy season. 

7. During winter solstice, due to slanting sunrays, the temperature goes down, that is winter season. 

8. Thus, there is monsoon climate with three distinctive seasons.