The rainfall along the Malabar Coast is primarily caused by the southwest monsoon winds, specifically the Arabian Sea branch of these winds. These moisture-laden winds blow from the Arabian Sea towards the Malabar Coast, bringing heavy rainfall during the monsoon season, which typically lasts from June to September. As these winds encounter the Western Ghats along the coast, they are forced to rise and cool, leading to orographic rainfall in the region. The southwest monsoon is the main factor responsible for the abundant rain in this area. In addition to the southwest monsoon, the Malabar Coast also receives some rainfall from the northeast monsoon, though it is less significant compared to the southwest monsoon rains. To summarize:

• The main winds accounting for rainfall along the Malabar Coast are the southwest monsoon winds (Arabian Sea branch).
• These winds bring heavy moisture during the summer monsoon season (June to September), causing most of the rainfall.
• The northeast monsoon also contributes minor rainfall from October to December.

This explains why the Malabar Coast is known for its heavy and consistent monsoon rains.