This Year's El Niño Is on Track to Break Records — and Panama Canal Traffic Is Already Feeling It

This year's El Niño is on track to be the strongest on record, threatening extreme weather across the globe and raising the odds that 2027 will be the hottest year ever recorded, climate scientists say. El Niño is the warm phase of a natural cycle in the tropical Pacific called the El Niño-Southern Oscillation, in which trade winds blowing east to west temporarily ease, letting warm water that normally piles up in the western Pacific slide back east and rise to the surface. "Stronger events mean that we can expect to see more of these expected El Niño impacts," said Michelle L'Heureux, ENSO team lead at NOAA's Climate Prediction Center, though she cautioned that none are guaranteed. Some effects are already being felt: Indonesia's long, intense dry season has fed wildfires that have burned hundreds of thousands of hectares.

Daily sea surface temperatures in the Niño 3.4 region of the Pacific are currently running about 2.6°C above a rolling 30-year average, according to the Climate Brink dashboard, which draws on NOAA's satellite-and-buoy sea surface record. Forecasts aggregated on the dashboard put El Niño on course to peak at a 3.9°C anomaly this November, well above the 3°C anomaly detected during the 2015 El Niño. NOAA puts the odds at 69% that this El Niño will be the strongest in its dataset going back to 1950.

Climate scientists Zeke Hausfather and Andrew Dessler calculate that El Niño will add a temporary 0.3°C on top of the long-term global warming trend, resulting in a 2027 temperature of 1.76°C above preindustrial levels — compressing into a single year as much warming as would otherwise be expected by 2037. "It's kind of a preview of the future," said Dessler, a professor at Texas A&M, though much of that heat will be focused in the equatorial Pacific. Scientists agree that climate change increases El Niño's impacts: a warmer, moisture-laden atmosphere can make El Niño-linked rains more extreme, and it dries out soils, deepening drought where El Niño brings drought.

The event is already reshaping global shipping. The Panama Canal will cut the number of ships passing through it starting next month because of a drought driven by El Niño, the canal's operator said. The number of vessels allowed through each day will fall from 36 to 34 starting September 3, and to 32 starting September 15, because of low water levels in the two artificial lakes that feed the canal. Rainfall in the canal's watershed from May to August is down 34% from its historical average, the Panama Canal Authority said, adding that El Niño could reduce it even more.

The canal, which handles about 5% of global maritime trade and around 40% of U.S. container traffic, has already lowered the maximum draft allowed for its largest ships to conserve water. In 2023, low lake levels forced the canal to cut daily transits from 38 to 22. On Wednesday, the government of Honduras placed 80% of the country on drought alert, as the same El Niño-driven conditions scorch harvests across Central America.