Why in News :
India’s southwest monsoon in 2025 covered the entire country by June 29, 9 days ahead of its usual schedule of July 8.
This is only the 10th instance since 1960 of the monsoon covering the nation by June.
Timeline of Events
- Kerala Onset: May 24 (8 days early)
- Nationwide Coverage: June 29 (9 days early)
- Pattern Observed: Early onset in South, East, and Northeast India; near-normal in Northwest; slight delay in Central India.
Key Drivers of the Early and Rapid Monsoon
Multiple Low-Pressure Systems
- June witnessed five low-pressure systems, acting as moisture magnets.
- These systems accelerated monsoon progression inland by pulling in rain-bearing winds.
Active Madden-Julian Oscillation (MJO)
- MJO is a moving system of wind, clouds, and pressure near the equator.
- When active over the Indian Ocean, it enhances convection (cloud formation and rainfall).
- In May–June 2025, an active MJO phase strengthened monsoon winds and boosted onset and spread.
Favourable Monsoon Trough Position
- The monsoon trough (an elongated low-pressure zone) remained south of normal.
- This southward shift intensified moisture inflow from oceans and enhanced rainfall in Central and North India.
Neutral ENSO Conditions
- ENSO (El Niño–Southern Oscillation) was in a neutral phase, neither El Niño (which suppresses rain) nor La Niña (which enhances it).
- A neutral ENSO allowed normal monsoon development, with no suppressing effects.
Neutral Indian Ocean Dipole (IOD)
- IOD measures temperature difference between western and eastern Indian Ocean.
- Neutral IOD in 2025 had minimal effect on the monsoon—no enhancing or suppressing role.
- Left other monsoon-driving factors (like MJO and low-pressure systems) to dominate.
Neutral Indian Ocean Dipole (IOD)
- IOD measures temperature difference between western and eastern Indian Ocean.
- Neutral IOD in 2025 had minimal effect on the monsoon—no enhancing or suppressing role.
- Left other monsoon-driving factors (like MJO and low-pressure systems) to dominate.
| UPSC Relevance GS1 – Important for climatology questions on Indian monsoon variability GS3 – Helps analyze localised flooding and drought events linked to erratic monsoonENSO, IOD, MJO are key topics in Geography optional & Prelims GS3 – Influences cropping pattern, sowing cycles, water availability GS3 – Disaster management tools and monsoon modeling insights Mains Answer Writing Practice Q. Discuss the major climatic and oceanic factors responsible for the early onset and rapid progression of the Indian monsoon in 2025. Also, comment on the implications for agriculture and disaster preparedness. (250 words) |