A severe ⁠heatwave gripped much of Europe on Sunday, with temperatures nearing 40 degrees Celsius (104 degrees Fahrenheit), prompting nationwide warnings, transport disruption and signs of strain on wildlife and at tourist hotspots.

The heat surge on June 21, the summer solstice in the northern hemisphere and typically the start of the three hottest months of the year, raised concerns of an early and persistent onset of ‌extreme conditions.

After several days of temperatures above 35 degrees, Italian authorities issued a red alert for June 21 in eight cities, including Bologna, Florence, Milan, and Turin.

In Rome, pilgrims in St Peter’s Square used parasols and umbrellas to shield themselves from the blazing sun as the Pope led a traditional Sunday prayer from a window of the Apostolic Palace.

The spike in temperatures is being driven by a mass of hot air moving north from the Sahara, fuelled by a strong high-pressure system known as the “African anticyclone.”

Meteorologists say the system is ⁠creating a so-called “heat dome,” trapping hot air over western and central Europe and allowing temperatures to build day after day. Madrid residents and tourists used fans ‌and drank plenty of cold drinks as they browsed the city’s famous El Rastro flea market.