April 2026 was one of the hottest Aprils on record for both land and sea, according to data from the EU's Copernicus Climate Change Service. Global average temperatures reached 1.43°C above pre-industrial levels, perilously close to the 1.5°C threshold set by the 2015 Paris Agreement. The findings have intensified concerns that another period of extreme global heat may be imminent, driven by unusually warm oceans and the potential return of a powerful El Niño.
Oceans Absorbing Record Heat
Sea surface temperatures are a critical indicator of how much excess heat the planet is absorbing. Copernicus data shows that average sea surface temperatures across much of the global ocean reached 21°C in April—the second-highest level ever recorded for the month. Only April 2024, during the last major El Niño event, was hotter. Parts of the tropical Pacific were especially warm, with record temperatures stretching from the central Pacific to the western coasts of the US and Mexico. Scientists described these conditions as “strong” marine heatwaves, a warning sign of the growing amount of heat building up in the planet's oceans, largely due to human-driven climate change.
The Intergovernmental Panel on Climate Change notes that the world's oceans have absorbed more than 90 per cent of the excess heat trapped by greenhouse gas emissions since 1970. Hotter oceans can intensify storms, damage marine ecosystems, and disrupt weather patterns worldwide. Samantha Burgess, strategic lead for climate at the European Centre for Medium-Range Weather Forecasts (ECMWF), said April's data showed “a clear signal of sustained global warmth.” She added: “Sea surface temperatures were near record levels with widespread marine heatwaves, Arctic sea ice remained well below average, and Europe saw sharp contrasts in temperature and rainfall. All hallmarks of a climate increasingly shaped by extremes.”
Super El Niño on the Horizon
Scientists are now closely monitoring the possible arrival of a potentially devastating “super El Niño” later this year. El Niño is a natural climate pattern triggered by unusually warm sea surface temperatures in the Pacific Ocean. It typically pushes global temperatures higher and can influence weather patterns worldwide, bringing droughts to some regions and floods to others. Forecasts from the ECMWF suggest that ocean temperatures in the central Pacific near the equator could rise to as much as 3°C above average by autumn. If that happens, it would rank among the strongest El Niño events ever recorded. Researchers generally classify a “super El Niño” as one where Pacific Ocean temperatures rise at least 2°C above average, though the term is not formally used by the US National Oceanic and Atmospheric Administration (NOAA).
The last major El Niño event in 2024 helped drive a series of global heat records. Scientists fear another one, on top of a warming climate, could bring even more extreme weather. Already in April, severe floods hit parts of the Arabian Peninsula, Iran, and Afghanistan, while drought conditions worsened in southern Africa. Tropical cyclones also developed across the Pacific.
Europe's Climate Split
Europe experienced two very different Aprils last month. While Southwestern Europe saw much warmer than average conditions, with Spain recording its hottest April ever, Eastern Europe was cooler than normal. The continent as a whole ended the month as only the tenth warmest April on record, but that figure masks these strong regional contrasts and recent trends. The stark differences highlight the complex ways climate change is reshaping weather patterns across the continent, from the Iberian Peninsula to the Baltic states.
The warming seas and potential super El Niño also have implications for European industries. For instance, Lufthansa has warned that rising fuel costs could hit annual profits, while Maersk's Q1 profit plunged 99% amid freight rate pressures and disruption in the Strait of Hormuz. Meanwhile, Spain set a Blue Flag record with 794 beaches and marinas for 2026, a testament to its coastal resilience even as marine heatwaves threaten ecosystems.
As the world braces for what could be another year of record-breaking heat, the data from April serves as a stark reminder of the urgency to address climate change. The coming months will be critical in determining whether the planet crosses the 1.5°C threshold, a limit that scientists warn could trigger irreversible changes to the Earth's climate system.
