Indian Climate, Monsoon Dynamics & Seasons
India's climate is classified predominantly as tropical monsoon, driven by seasonal reversals of planetary wind systems and differential thermal heating between the Asian landmass and the Indian Ocean. The Southwest Monsoon (June–September) accounts for over 75 percent of India's annual precipitation, advancing via two primary branches: the Arabian Sea branch and the Bay of Bengal branch. Key driving mechanisms include the northward migration of the Inter-Tropical Convergence Zone (ITCZ), Tibetan Plateau heating, Somali low-level jet streams, and tropical easterly jets. During winter, northern India receives vital precipitation from mid-latitude extratropical cyclones known as Western Disturbances, while the retreating Northeast Monsoon brings rainfall to coastal Tamil Nadu.
Key Concepts & Examination Highlights
- Mawsynram in Meghalaya's Khasi Hills receives the highest recorded average annual rainfall in the world (over 11,800 mm).
- The Southwest Monsoon strikes the Kerala coastline as the monsoon burst, typically around June 1 each year.
- Western Disturbances originate over the Mediterranean Sea and bring essential winter moisture for northern Rabi crops like wheat.
- El Niño Southern Oscillation (ENSO) in the central Pacific Ocean generally correlates with deficit monsoon rainfall across the subcontinent.