Seasonal Dynamics: Transition from Southwest to Northeast Monsoon Explained

The India Meteorological Department (IMD) officially declared the complete withdrawal of the Southwest monsoon from the Indian subcontinent as of October 15, 2026. This withdrawal marks the conclusion of the four-month rainfall season that serves as the primary water source for India’s Kharif agricultural cycle. The process of monsoon retreat is a gradual atmospheric phenomenon characterized by the weakening of the low-pressure trough over the Indo-Gangetic plains and the subsequent southward shift of the Inter-Tropical Convergence Zone (ITCZ). As the Southwest monsoon exits, India enters a critical transition phase. Concurrently, the Northeast monsoon (or retreating monsoon) has commenced over parts of South Peninsular India, specifically impacting coastal regions of Tamil Nadu, Andhra Pradesh, and Kerala. Unlike the Southwest monsoon, which is driven by moisture-laden winds from the Arabian Sea and the Bay of Bengal moving landward, the Northeast monsoon is fueled by winds blowing from the land to the sea, which pick up moisture as they traverse the Bay of Bengal. This phenomenon is vital for the water security of the southern peninsular states, which receive a significant portion of their annual precipitation during this window.