Early monsoon alert: Weather systems signal ahead-of-time arrival likely in India

Fresh forecasts from the European Centre for Medium-Range Weather Forecasts (ECMWF) suggest the southwest monsoon could make an early start, bringing much-needed relief from rising heat.

In Short

• India faces intense early heatwave with temperatures hitting 43-44C
• A number of factors will determine when the rains arrive
• Climate conditions, absence of El Nino favour early monsoon arrival

As April 2026 draws to a close, much of India is gasping under intense heat. Parts of north, central, and eastern India have seen temperatures soaring to 43-44C, with the India Meteorological Department (IMD) warning of further warming in the days ahead.

But there’s hopeful news on the horizon.

Fresh forecasts from the European Centre for Medium-Range Weather Forecasts (ECMWF) suggest the southwest monsoon could make an early start, bringing much-needed rain to southern India by as early as late May.

In 2025, forecasts had similarly indicated an early onset of rains over Kerala, with projections placing their arrival between May 27 and 29. However, the monsoon advanced even sooner than expected, noted Devendra Tripathi, founder of Mausam Tak.

The onset over the Andaman and Nicobar Islands also occurred ahead of schedule.

While multiple factors influence the monsoon’s progression, current indicators suggest a strong likelihood of an early arrival once again.

WHERE WILL MONSOON ARRIVE FIRST?

According to detailed sub-seasonal charts released this week, the monsoon is likely to reach the Andaman and Nicobar Islands between May 18 and 25.

Every year, moist winds bring travel from the Indian Ocean and bring rains to India.

Right now, models show strong winds blowing from the southwest building up over the southern Bay of Bengal and the Andaman Sea. These winds are expected to carry heavy showers, with rainfall 30 to 60 mm above normal in the islands during that week.

There’s even a moderate 20-40% chance of a tropical system forming north of the Andamans. Such systems often act like a booster that pulls more moisture and helps kickstart the monsoon season.

By the following week, May 25 to June 1, the monsoon pulse is forecast to push further west and north. Strong westerly winds are expected to develop over the southeast Arabian Sea, directing moisture straight towards India’s southwest coast.

This could bring above-normal rainfall to Kerala and southern districts of Tamil Nadu.

For millions in these rain-dependent regions, early showers would mean relief from the building heat and a timely start to agricultural activities. The models show a clear surge in rain clouds hugging the Kerala coast during this period.

WHAT WILL DECIDE WHEN MONSOON COMES?

A number of factors will determine when the rains arrive, said Tripathi, adding that El Nino will be absent when the monsoon arrives.

Then there's what is called the India Ocean Dipole (IOD). IOD is a phenomenon driven by differences in sea surface temperatures between the western and eastern Indian Ocean.

When the western Indian Ocean is warmer than the eastern part, a positive IOD drives more moisture toward the Indian subcontinent, typically strengthening the monsoon and bringing above-average rainfall, while a negative IOD tends to weaken the monsoon.

"Around the arrival of monsoon, there seems a good chance of the IOD favouring the monsoon," said Tripathi.

There's also the heat that needs to be addressed. The extreme heat India is experiencing this early in the year is bound to play a role in determining the upcoming monsoon.

When heat rises, then monsoon winds from the Indian Ocean that usually travel through the Arabian Sea and the Bay of Bengal, could do so much earlier.

"So if none of what is projected for late May changes in the atmosphere or the ocean, then there's a good possibility that the monsoon might arrive by around May 25," Tripathi said. "As of now, an early monsoon seems likely this year, too."

While the heat continues to permeate through the daily lives of millions in Southern India, if the models hold true, the much-awaited monsoon relief could arrive earlier than usual for southern India.

- Ends