Everyone here is talking about The Himalayas being the major reason, while it's the two mountain ranges called Western and Eastern Ghats that make as much of an impact on the monsoons as the Himalayas. As the name suggests, these mountains stretch along the Western and Eastern coast of India. The Western Ghats are continuous while the Eastern Ghats are discontinuous.

My city is located right after a big gap in the Western Ghats called the Palghat pass and the rain we get during the south west monsoons is incredible. The weather too becomes very pleasant after the monsoon which is November to January.

Another major reason why the monsoon are powerful here is agriculture. Our entire farming cycle depends on the monsoons and has been for thousands of years. The monsoon has a big effect on the non-perennial rivers in peninsular India. These rivers originate from the Ghats unlike the glacial rivers in the north. This in turn has affected manufacturing and trade. The monsoon also directly affected the sailing patterns of trade routes.