Early Arrival of Monsoon:
The India Meteorological Department (IMD) declared the onset of the southwest monsoon over Kerala on May 24, 2025, eight days ahead of the usual June 1 date.
- This marks one of the earliest monsoon arrivals in over a decade, last seen in 2009.
- The Southwest Monsoon is a seasonal wind system that brings over 70% of India’s annual rainfall during June–September.
- It plays a critical role in agriculture, water availability, and overall economic activity.
Factors Behind Early Monsoon Onset 2025:
- Madden-Julian Oscillation (MJO): Enhanced eastward-moving tropical disturbance boosted convection and rainfall over the Indian Ocean
- Mascarene High Intensification: Strong high-pressure system over the southern Indian Ocean aided in directing moist winds to Indian coastlines.
- Convection Surge: Rising heat and moisture movements increased vertical cloud build-up, bringing early rains.
- Somali Jet Strengthening: Cross-equatorial winds became stronger, accelerating the arrival of monsoon currents over Kerala and Karnataka.
- Heat Low Formation: Persistent low pressure over Pakistan and NW India created suction for moist monsoonal air.
- Monsoon Trough Activation: Elongated low-pressure zone stretching from Arabian Sea to Bay of Bengal activated rainfall over central India and NE India.
