A Very Strong El Niño Is Coming — Here's What That Means

On 13 August 2026, a US government weather agency called NOAA reported that El Niño was getting stronger and gave a greater than 90% chance that it would become a very strong event during the fall and winter of 2026-27.

El Niño is a natural climate pattern in the Pacific Ocean. Every few years, the ocean surface along the equator gets warmer than usual, and that extra heat shakes up weather patterns all over the world. The opposite phase, when the ocean gets cooler than normal, is called La Niña. Together, these two phases and the in-between state make up a cycle scientists call ENSO.

NOAA's August 13 forecast raised the odds from an earlier forecast on 9 August, which had put the chance of a very strong El Niño at 81%. Four days later, that number jumped above 90%.

The buildup has been going on for months. Back in March 2026, NOAA said there was a 62% chance El Niño would develop by summer and last through the end of the year. At that point, La Niña conditions were still in place, continuing from February 2026. The swing from La Niña to a potentially very strong El Niño in about six months is unusually fast, though forecasters had flagged it as a possibility in the spring.

The World Meteorological Organization (WMO), a United Nations agency that tracks global weather, had been watching the same thing. In April 2026, the WMO said El Niño was likely to develop by mid-year. By May, it put the odds at 80% for June through August. In July, it reported that a strong El Niño was developing and expected to intensify.

NOAA's latest forecast goes further than the WMO's July description. The difference comes down to a specific number. Scientists classify an El Niño as "very strong" when ocean surface temperatures in a part of the central Pacific rise to at least 2.0°C above normal, averaged over three months. NOAA now says there's a better than 90% chance of hitting that mark this fall and winter.

The broader context is about what happens next. A very strong El Niño acts like a giant switch for global weather. It shifts where rain and storms form across the Pacific, which then changes weather patterns far beyond the ocean itself. The effects can include wetter winters in the southern United States, drought in parts of Australia and the Western Pacific, and unusual temperatures across North America and Eurasia. Because the planet is already warming from climate change, El Niño adds extra heat on top of that baseline, which could push seasonal temperatures even higher.

The timing matters for a lot of people. NOAA expects El Niño to peak from October to December, which lines up with the fall harvest in the Northern Hemisphere and the planting season in the Southern Hemisphere. Farmers who grow grain, oilseeds, and tropical crops in regions sensitive to El Niño will be watching closely. Energy companies also pay attention, because El Niño can change how cold or mild the winter gets, which affects heating demand.

The high confidence in the forecast is worth noting. When scientists say there's over a 90% chance of something, it means their computer models — which simulate how the ocean and atmosphere interact — are in strong agreement. Forecasts made in August tend to be more reliable than ones made in spring, partly because of a self-reinforcing loop: warmer ocean water weakens the trade winds, and weaker trade winds let the water get even warmer. The quick jump in the odds between 9 and 13 August suggests that real-world measurements of ocean heat and wind patterns are matching what the models predicted.

The 2026-27 El Niño comes right after a La Niña that lasted into early 2026, so the tropical Pacific has flipped from one extreme to the other within a single year. Both NOAA and the WMO now agree not only that El Niño is here but that it is likely to be very strong. NOAA's next update, usually released on the second Thursday of each month, will show whether the ocean and atmosphere continue to reinforce the path forecasters have identified.

If this forecast holds, the 2026-27 El Niño would rank among the most intense on record. That matters not because El Niño itself is rare — it happens every few years — but because very strong ones disrupt weather, farming, and energy planning across so many parts of the world at the same time.