The Copernicus Climate Change Service said sea surface temperatures in April were the second-highest ever recorded for the month, with warming accelerating across parts of the Pacific Ocean as neutral conditions transition toward El Niño.

Samantha Burgess, strategic lead for climate at the European Centre for Medium-Range Weather Forecasts, said daily ocean temperatures in recent days had moved close to surpassing the previous records set in 2024.

“It’s a matter of days before we are back in record-breaking ocean SSTs again,” Burgess told AFP, referring to sea surface temperatures.

Copernicus said marine heatwaves reached unprecedented levels in waters between the tropical Pacific and the United States during April, reflecting broader warming trends tied to both natural climate variability and long-term greenhouse gas emissions.

Last month, the World Meteorological Organization said El Niño conditions could emerge between May and July. The climate phenomenon, linked to warming Pacific Ocean waters and shifting trade winds, alters global weather systems and raises the likelihood of drought, heavy rainfall and severe heat events.

Scientists say El Niño is unfolding against a backdrop of persistent global warming, with oceans absorbing roughly 90 percent of excess heat generated by human-driven emissions from fossil fuels.

The previous El Niño contributed to 2023 and 2024 becoming the second- and hottest years on record respectively, according to climate agencies. Some forecasters believe the developing event could rival the strength of the “super” El Niño recorded in the late 1990s.

Zeke Hausfather, a climate scientist at Berkeley Earth, said last week that a strong El Niño could significantly increase the chances of 2027 becoming the hottest year ever observed globally.

Burgess cautioned that forecasting the intensity of El Niño during the Northern Hemisphere spring remains difficult because of seasonal uncertainties in climate models. She said, however, that the event was already likely to have substantial global consequences.

“We’re likely to see 2027 exceed 2024 for the warmest year on record,” Burgess said, noting that El Niño’s strongest influence on global temperatures often emerges in the year after it peaks.In its monthly climate bulletin, Copernicus said April temperatures globally were 1.43 degrees Celsius above the 1850-1900 pre-industrial average, making it the third-warmest April on record.

The agency also reported Arctic sea ice levels remained near historic lows during April, while Europe experienced contrasting weather conditions that could increase the risk of drought and wildfires during the coming summer.

Climate researchers say the persistence of marine heatwaves, shrinking ice cover and rising global temperatures underscores the intensifying impact of climate change, even before the full effects of El Niño materialize.