The global average temperature in January was 1.75C higher than in pre-industrial times. Copernicus estimates that La Niña is not yet fully developed, and the world is currently in neutral conditions between the two phases. Other data patterns may differ, with US scientists showing last month that La Niña conditions were forming
January 2025 was the warmest month on record, continuing a streak of extreme global temperatures despite a shift towards the cooling La Niña weather pattern, European Union scientists said.
“So El Niño and La Niña are two sides of the same coin. So they’re part of what’s called the El Niño Southern Oscillation, which is this big ocean atmospheric circulation that can happen across the Pacific, about every 2 to 7 years. El Niño refers to when the waters in the central and eastern Pacific Ocean tend to be warmer than average, and La Niña is the opposite. When those waters are either warmer or cooler than average, it can affect the atmosphere above them all the way down to the tropical atmosphere. And think of it as the first atmospheric domino effect that falls. That’s why we care so much about it, even though we’re potentially thousands and thousands of miles away from the tropics or the central and eastern Pacific Ocean,” said scientist Tom Diliberto.
January was a heatwave, with 18 of the last 19 months seeing global average temperatures more than 1.5 degrees Celsius above pre-industrial times, according to data released by the EU’s Copernicus Climate Change Service. This was despite the world shifting away from the warming El Niño pattern, which helped make 2024 the world’s warmest year on record, and towards its cooler sister La Niña, which involves cooling equatorial Pacific waters and can curb global temperatures.
“So what you’re seeing on that graph is an extension of colder than average water that’s showing up across the central and eastern Pacific Ocean, which is represented in that blue color, and that’s the primary thing that we’re looking for for El Niño, or for La Niña. The main thing that we’ve been observing, we’ve been looking for this kind of colder than average water at the surface in the eastern Pacific Ocean, the central Pacific Ocean. What we’re seeing is really the development of La Niña. Now, La Niña is not just an oceanic phenomenon, it’s an atmospheric phenomenon. On this graph is an extension and a deepening of colder than average water across the central and eastern Pacific Ocean. Signs that La Niña is developing,” he added.
The global average temperature in January was 1.75C higher than in pre-industrial times. Copernicus estimates that La Niña is not yet fully developed, and the world is currently in neutral conditions between the two phases. Other data patterns may differ, with US scientists showing last month that La Niña conditions were forming.
“The biggest, most consistent impacts are in the tropics, because that’s where the El Niño and La Niña phenomena are happening. So there can be a tendency, El Niño can lead to drought conditions across the continent, across the Western Pacific Ocean and Indonesia. While it can bring average rainfall, particularly in South Africa, as well as throughout the northern or northeastern parts of South America. In the United States, we also tend to see that we have above average rainfall during El Niño, throughout the southern tier of the United States, but also in parts of Mexico,” said Tom Diliberto.
Scientists at Berkeley Earth and the UK Met Office have said that expectations were for 2025 to be the third warmest year on record and cooler than 2024 and 2023 due to the shift towards La Niña, although uncertainties remain about how the phenomenon will develop. The World Meteorological Organization, for its part, stresses that there is no evidence that climate change is increasing the frequency of El Niño, but acknowledges that natural phenomena such as El Niño and La Niña are occurring in the broader context of climate change caused by human activity.