Observing the Pacific Ocean change has an almost unsettling quality. It doesn’t make a big announcement; there isn’t a single storm or a Tuesday morning breaking story. Rather, over thousands of miles of equatorial water, sea surface temperatures start to gradually rise. Eventually, NOAA forecasters issue an advisory, and the entire story becomes clear. In 2026, that moment came again.
El Niño has formed in the tropical Pacific, according to NOAA’s National Weather Service, and the statistics supporting this claim are strong. Sea surface temperatures in the Niño-monitored region have a 63% chance of rising more than 2.0°C above average, according to forecasters. If that threshold is met, NOAA would categorize this as a “very strong” El Niño event, which would cause agricultural planners to start reevaluating their assumptions and emergency managers to sit up straight.
When equatorial Pacific temperatures rise at least 0.5°C above average for several consecutive months, El Niño, the warm phase of what scientists refer to as the El Niño–Southern Oscillation, or ENSO, forms. However, the temperature figure by itself doesn’t provide a complete picture. The breakdown of the Walker Circulation, a massive east-to-west air flow that typically controls the movement of heat and moisture across the Pacific, is what truly signals the arrival of El Niño. The entire atmospheric machinery above the ocean starts to reorganize when that circulation weakens and warmer water moves eastward toward South America. From there, the effects spread.
A moderate or strong El Niño winter typically follows a predictable pattern for the United States. Storm systems move across the southern tier of the nation as the jet stream over the northern Pacific moves southward. From California to the states along the Gulf Coast, more rain, snow, and unpredictable weather become the norm. In the meantime, portions of the Ohio and Tennessee valleys, as well as the Northern Rockies, frequently dry up. Winters in the northern states are frequently warmer. For farmers, water managers, and anyone else making plans based on seasonal weather assumptions, the difference is significant even though it’s a rearrangement of normal rather than a complete collapse of it.
In its most recent Global Seasonal Climate Update, the World Meteorological Organization stated unequivocally that climate models are now “strongly aligned,” and there is high confidence in El Niño’s onset and subsequent intensification. The “spring predictability barrier,” a time when forecast confidence is naturally lower, is still a problem, according to Wilfran Moufouma Okia, Chief of Climate Prediction at WMO. However, models would significantly improve after April. For the months of May through July, above-average land surface temperatures are predicted almost everywhere, with the signal being most noticeable over southern North America, Central America, the Caribbean, Europe, and northern Africa.
It’s important to note that NOAA is keeping an eye on everything. The Relative Oceanic Niño Index, or RONI, is a new monitoring tool that the agency formally adopted in February. Because RONI is updated monthly, it is more sensitive to the actual state of the ocean than the older Oceanic Niño Index, which calculates temperature departures using a fixed 30-year baseline. Researchers discovered a stronger correlation between it and variations in the Walker Circulation, which determines whether El Niño is actually occurring. It’s a subtle but significant improvement in the nation’s monitoring of one of the planet’s most important climate patterns.
It’s important to keep in mind the effects of the most recent powerful El Niño. 2024 was the hottest year on record due to the 2023–2024 event and background warming caused by greenhouse gas emissions. A warmer baseline means more energy and moisture available for heat waves and heavy rainfall when El Niño tips the scales, but climate change doesn’t seem to increase the frequency of these events. Every forecast that is currently being released is quietly supported by this context.
As this plays out, it seems like the world has become a little more adept at predicting the future. Compared to even ten years ago, the advisory systems are better coordinated, the models are more aligned, and the monitoring is sharper. The more difficult question is whether that planning results in significant action, such as utilities controlling demand, cities strengthening flood infrastructure, or farmers modifying planting schedules. El Niño 2026 is developing. The sea has moved. Whether or not the rest of us are paying enough attention will determine what happens next.
