Northeast Monsoon To Commence Soon: Week Long Rains Over South Peninsula

Key Takeaways:

• The Northeast Monsoon is likely to make a timely and energetic onset over South India, potentially coinciding with the withdrawal of the Southwest Monsoon.
• A low-pressure area over the Andaman Sea and a cyclonic circulation near the Gulf of Mannar are expected to intensify rainfall activity.
• Widespread rain is expected from October 15, with the rain belt expanding northwards towards 20°N from October 17.
• Heavy rainfall is likely across Tamil Nadu, Kerala, Karnataka and Andhra Pradesh, with the opening wet spell continuing beyond the middle of next week.
• Forecast Validity: October 13–22, 2026 (Next 10 Days).

The time is right and conditions are favourable for the timely onset of the Northeast Monsoon over South India. The wind pattern is getting aligned, and the winter monsoon rains are likely to make an energetic start. The opening spell may be long and intense enough to dispel fears of any shoddy start, as has happened on a few occasions in the past. The withdrawal of the Southwest Monsoon and the onset of the Northeast Monsoon may be ‘in tandem’, repeating the pattern of the last two consecutive years. The retreat of the Southwest Monsoon and the ingress of the Northeast Monsoon were simultaneous on 15th and 16th October in 2024 and 2025, respectively.

There are two triggers for the speedy onset of the Northeast Monsoon and the intensification of rainfall activity. There is a low-pressure area over the Andaman Sea, supported by a deep circulation, and another closed circulation over the Gulf of Mannar and Southwest Bay of Bengal, in proximity to South Coastal Tamil Nadu. The onset of the monsoon and its further performance, against the backdrop of a strong El Niño, will be rather interesting. The past record of El Niño-induced Northeast Monsoon rainfall has generally remained promising.

Light weather activity will start along the coastline today itself. The interiors of Tamil Nadu will have precursory showers tomorrow, ahead of the arrival of the Northeast Monsoon. The spread and intensity of rainfall will increase substantially from 15th October onwards. It will cover the complete South Peninsula below 15°N. From 17th October onwards, the rains will extend their reach to 20°N, and the activity will continue until past the middle of next week. Heavy rains will bear down on the interiors of the South Peninsula and will cover Tamil Nadu, Kerala, Karnataka and Andhra Pradesh. All five subdivisions falling under the Northeast Monsoon cover are expected to get drenched during the opening week of the monsoon.

Trending:

Southwest Monsoon Left With Last Leg: Withdrawal Likely To Complete Soon