Current Conditions

• An El Nino Advisory is in effect (latest update)
• El Nino conditions are now present, and are expected to continue through the winter of 2023-2024

• Latest Monthly Discussion from the Climate Prediction Center

Tropical Pacific Sea Surface Temperatures:

Tropical Pacific Sea Surface Temperature Anomalies:

What is the El Niño Southern Oscillation (ENSO)?

Most of the information here is courtesy of climate.gov.

The El Niño Southern Oscillation is a recurring climate pattern across the tropical Pacific. The two phases, El Niño (the warm phase) and La Niña (the cool phase), represent the opposite extremes in the ENSO cycle, with ENSO-neutral conditions the third phase where conditions are near average. This oscillation is characterized by differences in ocean temperatures, winds, surface pressure, and rainfall across the parts of the tropical Pacific, which can influence weather across the globe.

• El Niño: A warming of the ocean surface, or above-average sea surface temperatures (SST), in the central and eastern tropical Pacific Ocean. Over Indonesia, rainfall tends to become reduced while rainfall increases over the tropical Pacific Ocean. The low-level surface winds, which normally blow from east to west along the equator (“easterly winds”), instead weaken or, in some cases, start blowing the other direction (from west to east or “westerly winds”).
• La Niña: A cooling of the ocean surface, or below-average sea surface temperatures (SST), in the central and eastern tropical Pacific Ocean. Over Indonesia, rainfall tends to increase while rainfall decreases over the central tropical Pacific Ocean. The normal easterly winds along the equator become even stronger.
• Neutral: Neither El Niño or La Niña. Often tropical Pacific SSTs are generally close to average. However, there are some instances when the ocean can look like it is in an El Niño or La Niña state, but the atmosphere is not playing along (or vice versa).

Maps of sea surface temperature anomalies in the Pacific Ocean during a strong La Niña (top, December 1988) and El Niño (bottom, December 1997). Maps by NOAA Climate.gov

We focus on ENSO due to its significant impact on the global atmospheric circulation, which influences temperature and precipitation patterns across the globe. It is also one of the most skillfully predicted climate modes, giving us advanced notice of weather and climate patterns.

Wintertime El Niño (top) and La Niña (bottom) weather patterns across the United States.

Latest Forecasts from the Climate Prediction Center and the International Research Institute

Latest Probabilistic Forecast

Latest Model Guidance

El Niño Temperature and Precipitation Anomalies

Below are winter (December-January) temperatures and precipitation anomalies for El Niño episodes since 1950. These composites are not meant to be a forecast of expected conditions. Rather, they use historical data to highlight where ENSO phases can potentially impact temperature and precipitation. Other climate modes, as well as atmospheric variability, makes each ENSO event unique and make impacts different.

Weak El Niño Temperature Anomalies	Weak El Niño Precipitation Anomalies

Moderate/Strong El Niño Temperature Anomalies	Moderate/Strong El Niño Precipitation Anomalies

La Niña Temperature and Precipitation Anomalies

Below are winter (December-January) temperatures and precipitation anomalies for La Niña episodes since 1950. These composites are not meant to be a forecast of expected conditions. Rather, they use historical data to highlight where ENSO phases can potentially impact temperature and precipitation. Other climate modes, as well as atmospheric variability, makes each ENSO event unique and make impacts different.

Weak La Niña Temperature Anomalies	Weak La Niña Precipitation Anomalies

Moderate/Strong La Niña Temperature Anomalies	Moderate/Strong La Niña Precipitation Anomalies

Long Range Outlooks from the Climate Prediction Center

One Month Temperature Outlook	One Month Precipitation Outlook

Three Month Temperature Outlook	Three Month Precipitation Outlook

• NOAA Climate.gov - ENSO Main Page
• Climate Prediction Center - ENSO Main Page
• Earth Research System Laboratory - ENSO Main Page
• Climate Prediction Center - Long Range Outlooks
• Latest Monthly Discussion from the Climate Prediction Center