A Swiss weather balloon had to climb to an unprecedented 5,300 metres (17,400ft) before the temperature fell to 0C (32F), meteorologists have said, as a late summer heatwave and wildfires continue to pummel swathes of continental Europe.
A man was found dead in a blaze raging north of Athens on Monday as the Greek government warned of an “extreme” risk of fire across the country, while more than half of mainland France was placed under an amber heat alert.
MétéoSuisse said the zero-degree line – the altitude at which the temperature falls below freezing, considered a key meteorological marker particularly in mountainous regions – was measured at 5,298 metres overnight.
The figure, which was registered by a weather balloon flown from Payerne in western Switzerland, constituted “a record since monitoring began in 1954”, the service said, and surpassed the previous high of 5,184 metres that was “only set in July last year”.
The 0C line “affects vegetation, the snow line and the water cycle, so has a considerable impact on the habitats of humans, animals and plants alike”, MétéoSuisse said. It had averaged 2,570 metres above sea level from 1991 and 2020, fluctuating between 1,000 and 2,000 metres in winter, and 3,000 and 4,000 metres in summer.
In recent decades “anthropogenic climate change has caused the altitude of the zero-degree line to rise significantly in every season”, the service said, noting that successive records for the indicator had all been set in the past 10 years.
Experts have said an exceptional area of high pressure across continental Europe centred over the Alps has created a heat dome that is forecast to push temperatures to record or near-record levels in several regions until at least Wednesday.
In Greece, a shepherd who tried to save his animals was found dead as a fire raged near Boeotia, about 60 miles (100km) north of Athens. People on a beach and in two communities near the blaze were ordered to evacuate, AFP reported.
Another wildfire broke out on the island of Evia on Monday, while fires also continued to burn out of control for a third day in north-east Greece near the port city of Alexandroupolis, with 12 communities evacuated over the weekend. The minister for civil protection, Vassilis Kikilias, has called for “extreme public vigilance” nationwide.
In Spain, the state weather agency, Aemet, has placed five provinces in the southern region of Andalucía on amber heat alert, warning that temperatures are forecast to rise to more than 40C around Seville, Córdoba and in the Guadalquivir valley.
In the Canary Islands, firefighters were making progress, however, battling an out-of-control blaze on Tenerife that was started deliberately and has forced more than 12,000 people to flee their homes and has burned through more than 8,400 hectares (20,800 acres) of pine forest.
“The worst is behind us,” the Canary Islands’ regional leader, Fernando Clavijo, said. “Today, we will keep on working, consolidating the perimeters. We cannot talk about control yet – we’ll see if we can stabilise all the fronts.”
In France, record temperatures were expected in the Rhone valley, with temperatures set to peak on Tuesday and Wednesday. The most intense heat was forecast in the south, where the mercury is already pushing past 40C.
Fifty of the country’s 96 mainland departments were on amber heat alerts, with some expected to be placed on a maximum red warning over the next few days. “Records could be broken, notably on Tuesday in the Rhône valley,” MétéoFrance said.
Firefighters were battling a fire near the village of Chanousse in the south-east that had so far consumed about 100 hectares (nearly 250 acres) of forest, authorities said. (The Guardian)