The El Niño weather pattern is developing into one of the strongest on record, with potential to significantly impact global temperatures and rainfall, according to the UK's Met Office.
Scientists officially declare an El Niño when sea surface temperatures in a critical Pacific Ocean region exceed the average by 0.5 degrees Celsius (0.9 degrees Fahrenheit). Current measurements show these temperatures are more than 2 degrees Celsius (3.6 degrees Fahrenheit) above normal. Forecasts indicate that these anomalies could surpass 3 degrees Celsius (5.4 degrees Fahrenheit) later this year as El Niño approaches its peak.
This level of warming would be unprecedented in records dating back to 1950 and potentially the most powerful event since the 19th century. Deeper ocean temperatures, in some areas reaching 8 degrees Celsius (14.4 degrees Fahrenheit) above normal at a depth of 100 meters (330 feet), may be contributing to the intensification of El Niño by acting as a reservoir of warm water.
"We have many months to go while this event continues to develop and that's one of the reasons that we have increased confidence that this will be a record-setting event," said Dr. Zeke Hausfather, a climate scientist at Berkeley Earth, a U.S. research group. Some climate organizations project even stronger anomalies, potentially reaching 4 degrees Celsius (7.2 degrees Fahrenheit) above average. Hausfather noted that such an event could be the strongest El Niño in 500 to 1,000 years, though definitively confirming such ancient events is challenging.
The Met Office highlights that heat released from the ocean into the atmosphere drives these temperature increases and alters rainfall patterns worldwide. El Niño events are known to influence weather systems globally, often leading to drier conditions in some regions and increased precipitation in others. Historically, El Niño has been associated with drying trends in equatorial regions, including parts of South America, Africa, Southeast Asia, and Australia, while generally bringing wetter conditions to the southern United States.