A potentially strong El Niño climate pattern is expected to emerge this summer and persist through the rest of the year, according to the most recent official forecast from the National Oceanic and Atmospheric Administration (NOAA).
Meteorologists estimate a 62% chance of El Niño emerging between June and August. El Niño occurs when the trade winds weaken, allowing large volumes of warm ocean water to shift from the eastern Pacific toward the Americas.
“Although the evidence is still preliminary, this could be a very significant event in 2026 and extend into 2027,” says Daniel Swain, climate scientist at the University of California, Department of Agriculture and Natural Resources.
A strong El Niño would raise average global temperatures. The hottest years on record generally occur during active El Niño years, as this phenomenon happens when the eastern Pacific is warmer than normal.
“Its role in the global Earth system is to release heat from the ocean depths that was temporarily stored there,” says Swain. “El Niño allows that subducted heat to be brought to the surface.”
This dynamic manifested significantly in 2023 and 2024, when a long and intense El Niño pattern contributed to breaking global temperature records. 2023 set the record for the hottest year ever recorded on Earth, a record surpassed only by 2024 temperatures.
“If a strong El Niño develops, it will raise temperatures a bit in 2026, but it will have a particularly large effect on 2027 temperatures, putting that year on track to likely be the hottest on record after 2024,” says Zeke Hausfather, research scientist at Berkeley Earth and climate research lead at the technology company Stripe.
El Niño, a natural cyclical fluctuation, is just one of the factors driving this record heat. Global warming caused by burning fossil fuels from human activity is the main reason for the planet’s warming. Even without El Niño, last year ranked among the three hottest years on record.
El Niño also affects regional weather patterns worldwide. The southern United States typically experiences more rain and milder temperatures, which can help control droughts and reduce wildfire activity.
However, the American Southwest faces such severe drought that a wetter year won’t be enough to fully replenish reservoirs, according to a new analysis from the National Integrated Drought Information System (NIDS). Additionally, the extra global heat from El Niño can trigger even more severe droughts in other parts of the world.
On the other side of the US, El Niño hinders hurricane formation in the Atlantic Ocean, often coinciding with less intense hurricane seasons. However, El Niño provides limited protection, since a single intense storm hitting the coast can cause catastrophic damage, and climate change has driven Atlantic temperatures sky-high, fueling storm formation. Moreover, El Niño does nothing to ease storms forming in the Pacific.
Swain says El Niño’s regional patterns are its most dangerous effects. “That means more heat waves and noticeably higher temperatures, but perhaps most importantly what it means for everything else: more energy for storms, more intense rainfall, more severe droughts, more extreme wildfires.”
Source: npr.org