Geography · 26 Aug 2026

El Niño ENSO monsoon

Consider the following statements regarding the El Niño phenomenon:

  1. It is classified as occurring when sea surface temperatures in the eastern Pacific Ocean rise at least 0.5°C above the long-term baseline.
  2. It strengthens the Walker Circulation, thereby intensifying moisture-laden winds that feed India's southwest monsoon.
  3. The El Niño-Southern Oscillation (ENSO) cycle recurs at a fixed interval of exactly five years.
A1 only
B2 only
C1 and 2 only
D1, 2 and 3
This question is based on: The Biggest El Niño in a Century Isn't a London Story - It's a Latur Story
Take this in full test mode → Instructions for 26 Aug 2026
About this question

Why in news

The UK Met Office confirmed forecasts this week of an unprecedented El Niño signal, with sea surface temperatures potentially exceeding 3°C above baseline, while the UN's Copernicus Climate Change Service separately projects 2026 as a likely record-breaking year with below-normal rainfall already noted over India.

Why for UPSC

UPSC frequently tests whether aspirants understand El Niño as a mechanism (weakened Walker Circulation disrupting monsoon winds) rather than just a headline term - this question probes that causal chain plus the classification threshold and irregular periodicity, both classic distractor traps.

Prelims summary

El Niño is declared at ≥0.5°C eastern Pacific SST anomaly; it weakens the Walker Circulation and thereby weakens India's southwest monsoon; the ENSO cycle recurs irregularly every 2-7 years, with no fixed periodicity.

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