What Caused an ‘Early’ Monsoon Onset in India This Year?
The Indian monsoon, one of the most anticipated weather events in the country, arrived earlier than expected in 2025. Traditionally scheduled to begin around June 1st in Kerala, this year the southwest monsoon touched the southern coast by May 26 , setting off discussions among meteorologists, farmers, and climate experts alike. But what exactly triggered this premature arrival? Let’s explore the key factors behind this phenomenon. 1. Strong Madden-Julian Oscillation (MJO) Activity One of the most significant contributors to this year’s early monsoon onset was the Madden-Julian Oscillation (MJO) — a moving system of clouds, rainfall, winds, and pressure that travels around the tropics and influences weather patterns. In late May 2025, a strong phase of the MJO was positioned favorably over the Indian Ocean, boosting convection and rainfall in the region. This helped create low-pressure zones and enhanced moisture buildup — two critical components that trigger monsoon cond...