WMO El Niño/La Niña Updates
The WMO El Niño/La Niña Update is a quarterly bulletin that provides analysis of the current conditions and evolution of the El Niño-Southern Oscillation (ENSO) phenomenon.
Open the dashboard to access the Updates and view the past and current El Niño and La Niña events through interactive visualizations.
Oceanic and atmospheric indicators
Global climate centres may adopt their own definitions and apply a combination of different criteria to monitor and determine the onset of El Niño or La Niña events. These criteria typically include Sea Surface Temperature (SST) anomalies in specific regions of the tropical Pacific – most commonly the Niño 3.4 region – along with the magnitude and duration of these anomalies. Atmospheric indicators, such as the Southern Oscillation Index (SOI), are also considered. As a result, differences in the application of these criteria can lead to variations in the classification and timing of ENSO events across institutions.
The WMO El Niño/La Niña Update is based on several oceanic and atmospheric indicators, including:
- SST anomalies in the equatorial Pacific Ocean, especially in the Niño 3.4 region
- Atmospheric pressure variations, measured by the SOI, which reflects the difference in air pressure between Tahiti and Darwin, Australia
- Subsurface ocean temperature anomalies which indicate the presence of warm or cold water below the surface
- Trade winds and atmospheric circulation which influence ocean-atmosphere interaction
- Cloudiness and rainfall patterns, especially across the equatorial Pacific
Consensus Building
The Update is prepared through a collaborative effort between WMO and the International Research Institute for Climate and Society (IRI), with contributions from experts worldwide.
The Update takes into account predictions from the WMO Global Producing Centres for Seasonal Prediction, the WMO Lead Centre for Seasonal Prediction Multi-Model Ensemble and other major meteorological centres. Experts analyse and interpret past and current atmospheric and oceanic conditions, latest trends and historical ENSO behaviours, alongside predictions from various dynamical and statistical models to reach a consensus. The El Niño/La Niña Update assigns probabilities to El Niño, La Niña and ENSO-neutral conditions.
Frequency
The WMO issues updates every three months, but additional special updates may be released if conditions change significantly.
Purpose and Use
The Update:
- helps governments, humanitarian and disaster risk agencies, and policymakers prepare for climate-related impacts.
- supports agriculture and food security, water management, and energy sectors in planning for potential droughts, floods, or temperature changes.
- provides guidance for meteorologists worldwide to refine regional forecasts.
Archive
Archive of all El Niño/La Niña Updates can be found here.
Other WMO flagship products
Global Seasonal Climate Update
The WMO Global Seasonal Climate Update (GSCU) is produced by the WMO Lead Centre for Seasonal Prediction Multi-Model Ensemble. It provides global‐scale assessments of the ongoing and upcoming seasonal climate along with information on robustness of the available forecast signals. GSCU is issued every month. Archive of GSCU can be accessed here.
Global Annual to Decadal Climate Update
The WMO Global Annual to Decadal Climate Update (GADCU) is produced by the WMO Lead Centre for Annual to Decadal Climate Prediction. It is issued every year. GADCU can be accessed here.
The El Niño/La Niña Update, GSCU and GADCU are highly demanded and used by United Nations partners and humanitarian organizations. These products help planning humanitarian support to countries at high risk from El Niño and La Niña impacts. This gives society the opportunity to prepare for associated hazards, such as heavy rains, floods, and droughts.
State of the Climate reports
The WMO State of the Global Climate report provides a comprehensive assessment of the Earth’s climate, highlighting key indicators such as global temperatures, greenhouse gas concentrations, sea level rise and extreme weather events. It serves as a crucial tool for the general public, decision- and policymakers to understand climate trends and their impacts. The report is particularly relevant to the Conference of Parties under the United Nations Framework Convention on Climate Change, where it provides a scientific basis for decision-making, informs climate negotiations and supports the formulation of effective climate action strategies.
Complementing this global report, the Regional State of the Climate reports offer detailed analyses of climate conditions and trends in specific regions (Africa, Asia, Latin America and the Caribbean, South-West Pacific and Europe), providing regional insights into regional temperature anomalies, precipitation patterns, high-impact extreme weather and climate events and climate-related risks. Together, these reports inform global and regional responses to climate change, support adaptation planning efforts and guide disaster risk reduction strategies.