El Niño
The central and eastern tropical Pacific is unusually warm, with changes in the winds and rainfall above it.
The warmer phaseUnderstand El Niño
Start with the essentials. Explore the pictures, watch a video, or test what you’ve learned. No climate knowledge needed.
One cycle, three phases
El Niño is a recurring change in the tropical Pacific, where the ocean and atmosphere act together. It can shift weather patterns far away. It is not a storm travelling towards your country.
La Niña
The cooler counterpart. Winds and ocean conditions change too, shifting weather patterns in a different way.
The cooler phaseNeutral
Neither phase dominates. Neutral does not guarantee ordinary weather everywhere: other influences still matter.
Neither phase dominatesLearn more: NOAA’s introduction to the cycle ↗
How can one ocean change distant weather?
The ocean changes
Part of the tropical Pacific stays warmer or cooler than usual.
The air responds
Winds and tropical rainfall patterns change with the ocean.
Weather patterns shift
Some places may be wetter, drier, warmer or cooler. The season matters.
Think of the ocean as a store of warmth. The winds help move its surface water. When that arrangement changes, the places where air rises and rain forms can change too.
Those shifts can alter wider wind patterns. The effects depend on where you live and the season; they do not give every country the same weather.
Go deeper: what do the winds do?
Trade winds usually push warm water towards Asia. During El Niño, weaker winds allow warm water to spread eastward. Less cold water rises near South America. During La Niña, stronger trade winds help reinforce the cooler pattern.
Learn more: NOAA’s ocean-and-wind explanation ↗
Ask three different questions
What is happening now?
The official status is a diagnosis based on the ocean and atmosphere. A watch means a phase may develop; it does not mean that phase has started.
What may happen next?
The forecast gives chances for a future Pacific phase. Check the full three month period and the date the forecast was issued.
What could it mean here?
Use the dated regional outlook for rain, heat or farming context. Global phase chances cannot predict the weather in your town.
Learning example · not the current forecast
What does a 70% chance mean?
Imagine 100 possible outcomes represented by these dots. Seventy show El Niño, twenty show neutral and ten show La Niña. El Niño is most likely, but the other outcomes are still possible.
- El Niño: 70%
- Neutral: 20%
- La Niña: 10%
This is not a 70% chance of drought or rain in your town.
Rainfall amounts and chances are different
“85% of usual rainfall” compares an amount of rain with its usual amount. “85% chance” describes how likely an outcome is. Always read what the percentage measures.
A forecast value of 0% is not a promise that an outcome is impossible. Forecasts can change as observations and models provide new information.
Learn more: The official phase probability outlook ↗
The season and your location matter
Rainfall affects water supplies and farming; hot conditions affect outdoor work. ENSO is useful background for planning, alongside local forecasts and the water or resources actually available.
Southwest monsoon
El Niño is often associated with weaker summer monsoon rain over India, but it does not guarantee drought. Other ocean and weather influences can change the outcome.
Northeast monsoon
Historical research links El Niño with wetter northeast monsoons in southeastern peninsular India. That tendency is not a nationwide rain forecast, and each year can differ.
For decisions, read the current IMD outlook, then the relevant district or crop advice. The tracker’s India cards explain the dated outlook and useful steps.
Learn more: IMD’s monsoon guide ↗
Learn more: IMD journal research on the northeast monsoon ↗
See the current India inputs →Learn with short videos
These videos open on NOAA’s Ocean Today website, which also provides written transcripts. Start with the first, then follow your curiosity.
El Niño and La Niña explained
Start here: watch how Pacific water, winds and rainfall patterns connect.
While you watch
Video and transcript ↗Notice which way the warm water moves when the winds weaken.
How scientists observe and forecast
See how observations help scientists understand what the Pacific is doing.
While you watch
Video and transcript ↗Which measurements tell us more than ocean temperature alone?
The water cycle
Build the basics: how water moves between the ocean, air and land.
While you watch
Video and transcript ↗Think about why changes in the ocean can matter for rainfall.
Common questions, clear answers
Does El Niño mean drought everywhere?
No. Some regions can be wetter, others drier. The season and local weather matter, so a global phase is not a universal warning.
Is the ocean history chart a forecast?
No. It shows observed, overlapping three month averages. Recent values may be revised. An index value on its own does not replace NOAA’s official ocean-and-atmosphere diagnosis.
Learn more: NOAA’s RONI explanation ↗
Is El Niño the same as climate change?
No. El Niño is a recurring natural cycle; human-caused warming changes the wider climate it happens within. El Niño can add warmth in a particular year. One event does not explain every heatwave, flood or long-term trend.
Learn more: NASA’s El Niño guide ↗
How often does it happen, and how long does it last?
Episodes commonly recur every two to seven years, rather than on a fixed schedule. Many last around nine to twelve months, although some persist longer.
Learn more: NOAA’s explanation and fast facts ↗
Can I use this tracker for an emergency decision?
Use current official local warnings for immediate decisions. This tracker explains climate context and seasonal outlooks; it does not issue emergency alerts.
A quick check, not an exam
Try three everyday questions. Each answer explains the idea, and you can change your mind.
Question 1 of 3 · no timer
Your answers stay in this page. Nothing is submitted or tracked.Trusted places to learn more
El Niño, with maps and illustrations
Explore the ocean pattern and its wider effects through satellite images and diagrams.
Open the resource ↗The ocean and wind connection
Follow the movement of warm water, trade winds and cooler water rising from below.
Open the resource ↗India’s monsoon questions
Understand rainfall averages, the monsoon and the influences that change it.
Open the resource ↗Weather school for curious readers
Go beyond El Niño with lessons on the atmosphere, oceans, clouds and weather.
Open the resource ↗Why the tracker uses RONI
An optional explanation of the relative ocean index and the change in monitoring method.
Open the resource ↗Weather versus climate
Separate a day’s conditions from the patterns measured over many years.
Open the resource ↗Resources checked 11 October 2026. External websites may change. These are learning materials, not the tracker’s current forecast.
A small glossary
- ENSO
- The name of the whole Pacific ocean-and-atmosphere cycle: El Niño, La Niña and neutral.
- Trade winds
- Winds that usually push tropical Pacific surface water westward, towards Asia.
- Anomaly
- A difference from the usual value for a place and time of year. It does not mean a mistake.
- Three month season
- An overlapping period such as October–December. The next period, November–January, shares two months.
- Long-period average
- A multi-year benchmark used to describe what is usual. “Normal” in an outlook is a defined range around that benchmark.
- RONI
- Relative Oceanic Niño Index: Pacific warmth compared with warmth across the wider tropics. It is one observed measure, not a diagnosis on its own.
Definitions follow NOAA’s ocean explanation, CPC’s RONI method and IMD’s monsoon guide linked above.