Climate Lab
This forecast will be updated regularly.
Sea surface temperature anomaly in the central equatorial Pacific Ocean
July 10, 2026 at 6:00 a.m. EDTJust now
A much-anticipated El Niño that developed this summer could grow to become one of the strongest ever recorded, its cascading effects spilling into the rest of the year and the next one.
But just how extreme could this get?
The latest data released in early July shows ocean temperatures in the central equatorial Pacific Ocean— a key zone where El Niño’s strength is measured — had been record warm for about a month. And forecasts show temperatures continuing on a record trajectory for the rest of the year, reaching an average peak of around 3.9 degrees Celsius (7.0 degrees Fahrenheit) above average in December — about a degree higher than a record-breaking El Niño in 2015.
Because raising the temperature of the ocean requires far more energy than warming the land, that shift would represent an extraordinary amount of warming.
El Niño index
Sea surface temperature in the central equatorial Pacific relative to the average from 1993 to 2016
We’re tracking just how feverish those ocean temperatures could become. In the graphics above, forecast scenarios, represented by the red boxes, show this El Niño reaching heights by the end of the year that have never been observed before.
These graphics and the ones that follow will be updated regularly as this El Niño — and its global impact — grows through the end of the year.
An El Niño of this magnitude is expected to drive significant weather impacts, which could end up stronger and more longer-lasting. Global temperatures could reach new highs, while patterns of drought, floods, heat and humidity shift across the planet.
Already, sea surface temperature forecasts suggest this El Niño will top the most historically intense events on record, potentially by a wide margin. Those events occurred in 1877-78, 1888-89, 1972-73, 1982-83, 1997-98 and 2015-16.
What is El Niño?
El Niño is a natural warming of ocean waters in the eastern and central equatorial Pacific that develops every two to seven years.
December sea surface temperature forecast
relative to the average from 1993 to 2016
Central equatorial Pacific
monitoring region
December sea surface temperature forecast
relative to the average from 1993 to 2016
Central equatorial Pacific
monitoring region
Warmer seas that develop in this remote part of the world, highlighted in the above map, cause thunderstorm patterns to change there. That has cascading effects on weather patterns across the planet as those storms transfer heat from the ocean to the atmosphere.
In other words, what happens in the tropical Pacific doesn’t stay there.
These changes in thunderstorm patterns cause storm-carrying ribbons of wind in the upper atmosphere, called the jet streams, to change speed and direction, affecting weather patterns around the globe.
The current El Niño was kick-started by a wind burst in a remote part of the western Pacific during December. Those wind bursts kept forming, shifting copious amounts of warm water west-to-east across the Pacific through oceanic features called Kelvin waves. That has led to summerlike weather in Peru during winter.
How will this El Niño impact the weather through September?
The latest outlook of possible extreme weather ripple effects from this year’s El Niño is based on three-month forecast data released in early July.
These outlooks don’t predict specific weather events. Instead, they show where unusually extreme climate conditions are more likely, often because of frequent storms or persistent departures from normal weather patterns.
This year’s phase is expected to have a profound, upward influence on global temperatures, with more than an 80 percent chance for 2027 to become the warmest year on record.
That’s because warmth that builds up along the equator in the Pacific Ocean gets released into the atmosphere and spreads around the planet.
Through September, around 2.8 billion people across the planet have at least a 10 percent chance of experiencing temperatures that are in the top 5 percent of historical values for the time of year.
Chance of extremely high temperatures
Probability of average temperatures exceeding the 95th percentile from 1981 to 2025
Chance of extremely high temperatures
Probability of average temperatures exceeding the 95th percentile from 1981 to 2025
These places may experience very unusual warmth compared with what is normal:
- The Central and Eastern United States
- The Caribbean, Central America and northern South America
- Western Europe and large parts of Africa
- The Middle East, India, Indonesia and some Pacific Island nations
El Niño causes cells of high and low pressure to shift and, in some areas, become stronger and more persistent.
These changes in atmospheric circulation increase the risk of drought in some regions and extreme rainfall in others.
Around 1.4 billion people live in areas that have at least a 10 percent chance through September for much less precipitation than normal, while 757 million live in areas where there is at least a 10 percent chance for excessive precipitation.
Chance of extremely dry conditions
Probability of rainfall below the 5th percentile
from 1981 to 2025
Chance of extremely dry conditions
Probability of rainfall below the 5th percentile from 1981 to 2025
These places have a chance of seeing extremely dry conditions compared with what is normal:
- Central America, parts of the Caribbean and northern and western South America
- Parts of Northern and Western Europe, as well as northeastern Africa
- Swaths of the Middle East, India, Indonesia and some South Pacific islands
Chance of extremely wet conditions
Probability of rainfall exceeding the 95th percentile
from 1981 to 2025
Chance of extremely wet conditions
Probability of rainfall exceeding the 95th percentile from 1981 to 2025
On the other hand, these areas may see much more precipitation compared with what is normal, which can lead to flooding:
- Parts of the U.S. Intermountain West
- Large parts of South America, including Peru, Ecuador, Chile, Bolivia and southern Brazil
- Areas near the Mediterranean Sea, including southern Europe and northern Africa
- Parts of southern Africa, as well as Somalia
- Pockets of southern Asia from India to Thailand, as well as Kiribati, Guam and the Northern Mariana Islands in the Pacific Ocean
Although El Niño is an important driver of global weather patterns, it isn’t the only one. These predictions incorporate many different factors that influence climate. Seasonal outlooks like this are also most accurate near the tropics.
These patterns of potentially unusual weather can shift with each forecast update. For example, the impact across the U.S. typically peaks during winter, when the West, South and East can frequently face heavy rain — and the colors on the maps will probably reflect that threat as winter approaches.
Chance of extremely high humidity
Probability of average humidity exceeding the 95th percentile from 1981 to 2025
Chance of extremely high humidity
Probability of average humidity exceeding the 95th percentile from 1981 to 2025
In some regions, El Niño will also contribute to much higher humidity than normal.
That includes areas such as the Intermountain West, where a more robust monsoon pattern is expected to develop this summer, as well as near the Gulf Coast.
Humidity much higher than normal is also possible in Europe, where frequent heat domes have caused a marine heat wave to develop in coastal waters.
How much is climate change to blame?
Ocean temperatures are rising, mostly because of climate change. That includes the key stretch where El Niño is measured.
To distinguish warming caused by El Niño from the long-term warming of the oceans, scientists have developed a new climate change-adjusted index, which is now used by the National Oceanic and Atmospheric Administration and climate agencies in Europe, Australia and New Zealand.
Rather than looking only at temperatures compared with the average in the central equatorial Pacific, the new index compares temperatures in that region with the average temperature across all tropical oceans. In other words, it measures how much warmer the El Niño region is than the rest of the tropics.
That relative temperature difference is closely tied to shifts in tropical thunderstorm activity, which helps drive the changes in weather patterns associated with El Niño around the world.
The gap between the traditional El Niño index and this new relative index represents the amount of background ocean warming included in the traditional measurement. The latest forecast suggests that gap will be around 0.55 degrees Celsius (1.0 degree Fahrenheit) during El Niño’s expected peak in December.
While that may not sound like much, even that additional warming increases the atmosphere’s moisture-carrying capacity. Air can hold about 4 percent more water vapor for every degree Fahrenheit of warming, which can amplify precipitation extremes around the planet.
About this story
Climate data used in this story comes from the Copernicus Climate Change Service, including the ECMWF model for predictions and the ERA5 atmospheric reanalysis for historical comparisons. Sea surface temperature forecasts for the current El Niño are compared with retrospective forecasts from 1993 to 2016, called hindcasts, to determine where conditions may be unusually warm or cool. The maps of potential weather extremes show chances of temperatures, precipitation and humidity being above the 95th percentile or below the 5th percentile, compared with hindcast data from 1981 to 2025. This provides insights into the potential for climate conditions that deviate significantly from the norm and that could have a significant impact on people’s lives. New forecast information is released each month after the 6th, with each update looking another month into the future. The chart comparing this El Niño with past events will be updated more regularly.
