El Niño is coming, and the world's top climate authority is urging governments to brace for the fallout.

The World Meteorological Organization (WMO) issued a climate advisory this week warning that the powerful Pacific Ocean pattern is officially developing and poised to disrupt global weather over the coming months, driving up temperatures and raising the risk of drought, heavy rainfall and heat waves around the world.

The tone from the top was urgent.

"El Niño is arriving on our doorstep in the coming months with 90% certainty," United Nations Secretary-General António Guterres warned in a video statement. "El Niño conditions will pour fuel on the fire of a warming world. Impacts will hit even harder, travel even farther and cross borders with devastating speed."

El Niño is a periodic warming of water in the central and eastern equatorial Pacific Ocean that can affect global weather patterns for months. According to the WMO's update, there is an 80% likelihood of El Niño conditions fully establishing themselves during the June to August window, with probabilities soaring near or above 90% that it will persist through at least November.

(MORE: Your complete guide to everything El Niño)

For those in its path, the agency's message was simple: Start preparing now.

"We need to prepare for a potentially strong El Niño event, which will exacerbate drought and heavy rainfall and increase the risk of heat waves both on land and in the ocean," said WMO Secretary-General Celeste Saulo. "The most recent El Niño, in 2023-24, was one of the five strongest on record and it played a role in the record global temperatures we saw in 2024."

While the event will emerge this summer, NOAA's Climate Prediction Center notes that its true strength will likely peak later in the year, showing an almost 60% chance of becoming a strong event by autumn and a one-third chance of developing into a rare "super El Niño," an event where ocean surface temperatures run at least 2°C above average. There have been only five such events since 1950, the most recent in 2015-16.

Models trending stronger, but a scientific catch remains

Computer forecast models have trended increasingly bullish. Several ensemble models suggest that ocean surface temperatures in the equatorial Pacific could top out at more than 2.5°C above average by autumn, which would rank this event among the most intense on record.

"The present state is close to the conditions at the same time in 1997," says Paul Roundy, a University at Albany professor and El Niño expert. The notorious 1997-98 event stands as one of the strongest super El Niños in modern history.

However, nature rarely follows a perfect script. NOAA-CPC struck a more cautious tone in its May outlook, citing "substantial uncertainty in the peak strength of El Niño."

On social media, Roundy raised a related meteorological caveat: The same intense westerly wind bursts that recently gave this developing El Niño a head start could eventually sap its power. By triggering increased evaporation, these winds can extract heat from the ocean, potentially capping how strong this El Niño can ultimately get.

So, for now, the short answer on a record-strong event is, to quote legendary Brit rockers Oasis, "definitely maybe."

While the WMO avoids using the non-standardized term "super El Niño," meteorologists around the world are watching the Pacific with intense scrutiny.

Fueling the fire: a deep subsurface heat reservoir

What has scientists particularly focused is the volume of heat lurking just beneath the ocean surface. WMO observations show that subsurface temperatures across the tropical Pacific are running more than 6°C (about 11°F) above average. This underwater heat reservoir is continuously feeding the surface warming.

The climate change connection

The WMO stresses a key nuance regarding climate change: There is currently no definitive evidence that global warming increases the frequency or inherent strength of El Niño events themselves. Instead, a warmer atmosphere and ocean act as an amplifier. Climate change packs the environment with extra energy and moisture, intensifying the heat waves, droughts and torrential rains that El Niño naturally triggers.

What this means for global and U.S. weather

Because El Niño alters the flow of the jet stream, its ripple effects span the globe. Here is what the combined data from the WMO and weather.com meteorologists project:

1. The Atlantic and Pacific hurricane seasons

A strong El Niño is typically good news for the U.S. East Coast. It generates increased sinking air and hostile wind shear across the Atlantic Basin, which tears developing tropical systems apart. Accordingly, NOAA is forecasting a below-average Atlantic hurricane season this year, though as the 2023 season showed, that's not guaranteed. Conversely, the Central and Eastern Pacific hurricane seasons are expected to be more active than usual.

(MORE: How possible super El Niño could affect hurricane tracks)

2. A shift in the U.S. winter jet stream

For the United States, the strongest impacts will take center stage as the seasons turn. In winter, a robust El Niño typically turbocharges the subtropical branch of the jet stream.

• The Southern Tier: Expect a wetter winter across the southern third of the country, from southern California and the Desert Southwest through Texas and into Florida. If enough cold air aligns, this setup can bring higher snowfall potential to these regions.
• The Northern Tier: A stronger El Niño typically leaves the northern U.S. milder and drier than average, particularly across the Pacific Northwest, Northern Plains and Midwest.

3. Global precipitation patterns

The WMO's Global Seasonal Climate Update highlights typical El Niño dry and wet zones:

• Wetter conditions: Typically favored over parts of southern South America, the southern U.S., Central Asia and parts of eastern Africa over the lifecycle of the event.
• Drier conditions: Forecast for Central America, northern South America, the Caribbean, Australia and Indonesia.

Human and economic stakes

For all the talk of probabilities and ocean anomalies, a strong El Niño is ultimately measured in its toll on people, and that's what has officials urging action now rather than later.

The WMO calls its El Niño updates the world's most authoritative source of guidance for governments, humanitarian agencies and climate-sensitive sectors like agriculture, health, energy and water management. The reason is simple: When the pattern shifts global rainfall and temperatures, the consequences land on harvests, water supplies and public health.

Those consequences won't fall evenly. As the WMO stresses, El Niño's fingerprints vary by region and from one event to the next, meaning some areas will face drought and crop stress while others contend with flooding. Several regional forecasts already point to trouble. The northern Greater Horn of Africa and South Asia are bracing for below-normal rainfall during their critical wet seasons, while Central America expects drier and warmer conditions.

"Advance seasonal forecasts and early warnings are vital to save lives and cushion the impact on our economies and our communities," Saulo said. That's why the agency is urging governments, humanitarian groups and climate-sensitive industries to plan ahead while there's still time.

Global temperature records: 2026 and possibly beyond

With global baseline temperatures already highly elevated, the heat released by this El Niño makes new global temperature records in 2026 a "slam dunk," in the words of weather.com's analysis.

There's a longer-term wrinkle, too. The WMO notes that El Niño's impacts on global temperatures are typically most pronounced in the second year after the event develops. That means while 2026 will likely feature extreme heat stress and worsening droughts, the planet could feel even more of this El Niño's thermal influence in 2027, though much depends on how strong the event ultimately becomes.