Event

End of La Niña & onset of ENSO-neutral conditions in March 2025

Agency

NOAA (National Oceanic & Atmospheric Administration, USA)

Previous Phase

A short, mild La Niña phase from late 2024 to early 2025

Current Phase

ENSO neutral sea surface temperatures (SSTs) & atmospheric indicators no longer meet La Niña thresholds

SST Measurement

Niño 3.4 region SST ~ -0.01°C (much warmer than La Niña threshold of -0.5°C)

Ocean Indicators

Warm water spread westward across eastern Pacific
Subsurface cold water shrank

Atmospheric Indicators

Trade winds still strong but lack of cold SSTs ends La Niña classification

Projection (2025)

>50% chance ENSO-neutral continues through August–October; ~43% chance it lasts into early winter

Spring Predictability Barrier

Forecast confidence drops during spring due to natural atmospheric variability

Historical Record

Recent La Niña may not qualify for historical inclusion (didn't meet 5 overlapping 3-month criteria)

SST Anomaly (Niño 3.4)

≥ +0.5°C above normal

≤ –0.5°C below normal

Between –0.5°C & +0.5°C

Trade Winds

Weakened or reversed

Strengthened

Near-normal

Walker Circulation

Weakened (eastward shift)

Strengthened (westward shift)

Balanced

Rainfall in Pacific

Increased in east-central Pacific, dry in west

Enhanced in western Pacific, dry in east

Typical seasonal variability

Effect on Indian Monsoon

Suppressed monsoon (weak rainfall)

Strengthened monsoon (good rainfall)

Uncertain & variable

Impact on South America

Flooding in Peru, drought in Amazon

Drought in Peru, floods in Australia

Normal seasonal variation

Global Influence

Warming events globally

Cooling events globally

No significant global anomaly

Duration

9–12 months

9–12 months

Transitional (can last months)

Monsoon Onset

Delayed

Early or on time

Normal or slightly delayed

Total Rainfall

Deficit (~10–20% below normal)

Surplus (~5–15% above normal)

Near-normal but unpredictable

Intra-seasonal Variability

Higher dry spells

Better distribution

Unstable, harder to forecast

Cyclone Activity (Arabian/Bay)

Suppressed in Bay of Bengal

Enhanced in Bay & Arabian Sea

Variable

Temperature in India

Warmer summer & drier soil

Cooler summer, better soil moisture

Near-normal but unpredictable

Agriculture Impact

Reduced kharif yields, food inflation

Boost in crop output, better sowing

Depends on local patterns

Reservoir Levels

Low inflow

High inflow

Balanced or region-specific variability

Policy Implication

Need for drought planning, import support

Fertilizer demand, irrigation stable

Uncertainty in contingency planning

PRACTICE QUESTION

Q. While La Niña & El Niño offer climatic signals unpredictability of ENSO neutral phases complicates policy response. Analyze how ENSO neutral conditions affect Indian climate resilience strategies.