Last month became the warmest June ever observed in Western Europe, with temperatures exceeding the 1991–2020 average by more than three degrees Celsius (5.4 degrees Fahrenheit), according to the European Union’s Copernicus Climate Change Service.

In a statement released Thursday, the climate monitoring agency reported that the region’s average temperature climbed to 20.74C (69.33F). The surge was largely driven by a powerful heatwave in the latter half of the month that shattered records in several countries.

On a global scale, the average temperature reached 16.54C (61.77F), which is 0.56C (1F) above the June average for the 1991–2020 reference period.

Copernicus also noted that this June was 1.39C (2.5F) warmer than the estimated pre-industrial June average recorded between 1850 and 1900.

The intense heatwave, which came after a series of other extreme weather events, underscored the mounting challenges linked to climate change. At the same time, unusually dry conditions in southwestern Europe fueled outbreaks of wildfires.

Sea surface temperatures across non-polar oceans averaged 20.86C (69.55F) in June, marking the highest level ever measured for the month, the service reported.

‘Heat dome’

Europe continues to warm faster than any other continent, with shifts in atmospheric circulation contributing to increasingly frequent and severe heatwaves.

The June heatwave was intensified by a “heat dome” phenomenon, a high-pressure system that traps hot air over a region much like a lid placed on a boiling pot.

Thousands of fatalities have been associated with the heatwave, particularly in France, Spain, and Belgium.

An analysis found that more than two-thirds of Europe’s population — around 410 million people — experienced temperatures exceeding 35C (95F) during the June heatwave.

Samantha Burgess, strategic climate lead at the European Centre for Medium-Range Weather Forecasts, which oversees Copernicus, explained that elevated humidity played a major role in amplifying the heat’s impact.

“The atmosphere was exceptionally humid, which meant there was little nighttime relief. We experienced several consecutive tropical nights,” she said.

The Mediterranean Sea endured its own record-setting marine heatwave, while unusually high temperatures also affected Europe’s Atlantic coastlines, placing additional stress on marine and coastal ecosystems.

“Warmer seas reduce cooling overnight because there is less refreshing air moving inland. The usual sea breeze effect weakens,” Burgess added.

Persistent dry weather heightened the risk of drought in Eastern Europe and supported wildfire activity across the Iberian Peninsula and southern France, Copernicus stated.

Copernicus routinely releases assessments of global surface temperatures, sea ice coverage, and precipitation levels. These reports are based on advanced computer modeling that integrates billions of data points collected from satellites, ships, aircraft, and ground-based weather stations worldwide.