(2) The southwest monsoon brings rains towards the end of summer as the high pressure built in the Indian Ocean pushes the wind masses towards the low pressure formed on land. It’s the temperature variation between the sea and the landmass – sea air being cooler and land being warmer– that causes the action. Also, we have to take an important factor called Temperature Gradient into consideration. It is the Temperature Variation Between The landmass and the surrounding sea.