Europe trapped under heat dome

Europe is enduring an intense heatwave with temperatures exceeding 40°C in central regions and surpassing 30°C in parts of Norway, as a high-pressure system traps warm air like a “lid on a pot,” according to Norway’s Meteorological Institute.

Statsmeteorologist Aslaug Skålevik Valved told Dagbladet the phenomenon—known as a heat dome—creates a blocking pattern that forces warm air downward, compressing and heating it further. The stagnant system sustains high temperatures and humidity over prolonged periods.

“It’s like a greenhouse,” Valved said. “The sun heats the air, and the ‘lid’ won’t let it escape.”

The heatwave has broken records in France, where Wednesday marked the hottest day since measurements began in 1947. Authorities reported multiple deaths, closed schools, halted train services, shut down a nuclear reactor, imposed alcohol bans, and canceled events. Red alerts for extreme heat cover much of France, Germany, Croatia, Benelux, Slovakia, and Switzerland.

Valved noted the current heatwave should ease by the weekend, shifting eastward, but warned of more to come this summer. She attributed the increasing frequency and early onset of heatwaves to climate change.

In Norway, a heatwave is defined as five consecutive days above 27°C at a single station. Several locations, including Drammen, Nelaug, and Byglandsfjord, are approaching this threshold after temperatures spiked midweek.

Valved urged caution for vulnerable groups—elderly, children, and pets—and reminded the public to stay hydrated and avoid prolonged sun exposure.