Why Europe Is Sweltering: WMO Explains the Forces Behind Record Heat

The World Meteorological Organization (WMO) has identified the key drivers behind Europe's record-breaking summer heat wave, pointing to unusually warm ocean waters and severely dry soils as the primary culprits.

John Kennedy, the WMO's head of climate information, explained that the Mediterranean Sea and the waters west of Europe have been exceptionally warm. These marine heat waves provide the background warmth that high-pressure systems build upon, intensifying the heat felt on land.

Kennedy also highlighted the role of dry soil. Wet soil is harder to warm, but as it dries out, it becomes much easier for the weather to heat the land and the air above it. These factors are converging to produce the extreme temperatures seen this year.

The extreme heat, which began in May, has fueled major wildfires, prolonged drought, and set new national temperature records across the continent. It has also been linked to thousands of projected heat-related deaths.

WMO spokesperson Clare Nullis warned that the water deficit in parts of Europe is severe and will not be quickly resolved. She noted that some regions, particularly in Hungary, Serbia, and near the Adriatic Sea, would need between 250 and 350 millimeters of additional precipitation to normalize the surface water balance deficit that has accumulated since April.

"Even if we had normal rainfall starting immediately, it will take a long time to redress the balance," Nullis said.

The heat waves have also pushed the average temperature for the June-July period above the previous record set in 2022, according to the European climate agency Copernicus. Globally, 2026 is currently the third-hottest year on record, behind 2024 and 2025, but scientists say there is an increasing chance it could become the hottest year ever by December.