EnvironmentWednesday, 23 September 2026·The Hindu - Environment
El Nino and Tamil Nadu northeast monsoon: Niño 3.4 index, WMO warning, and 2026-27 rainfall outlook
A 2026 explanation piece says a strong El Nino, with Niño 3.4 at +2.51°C, is being watched for its impact on Tamil Nadu’s northeast monsoon.
Key highlights
Direct fact
In September 2026, The Hindu reported that the Niño 3.4 index over the central-eastern Equatorial Pacific had risen to +2.51°C, and meteorologists in Chennai were tracking its likely effect on Tamil Nadu’s northeast monsoon in 2026-27.
Key specifics
- Niño 3.4 index: +2.51°C, compared with the El Nino threshold of +0.80°C.
- The strong El Nino is expected to persist till May or June 2027.
- The World Meteorological Organisation warned that a very strong El Nino can shift rainfall and temperature patterns worldwide.
- 2024 was the warmest year on record, crossing the 1.5°C Paris Agreement threshold.
- Sivananda Damodara Pai, Head, Regional Meteorological Centre, Chennai, said El Nino can alter cyclone tracks and monsoon behaviour.
Exam lens
Environment and climate-change MCQ focus: Niño 3.4 index, El Nino threshold, WMO warning, Chennai RMC, and the link between El Nino and Tamil Nadu’s northeast monsoon are the key one-liners.