Why is it so hot in Europe? This summer’s heatwaves explained

From record-breaking heatwaves to devastating wildfires, countries across Europe have been battling the effects of extreme weather.

Here is what to know:

Why is it so hot in Europe?

The World Meteorological Organization said this month that July began with the hottest week on record.

The extreme temperatures came after climate change and El Nino – a cyclical weather phenomenon that warms the Pacific Ocean – combined to create the hottest June on record.

Europe this week also experienced some of its hottest temperatures so far this summer thanks to a so-called heat dome stretching over its south.

A high-pressure anticyclone named Cerberus, a reference to the monstrous watchdog of the underworld in Greek mythology, began moving in from the south on July 10. It was followed by Charon, named for the mythological ferryman who transported souls from the world of the living to that of the dead. That weather system saw parts of Greece, Spain and Italy record temperatures above 45 degrees Celsius (113 degrees Fahrenheit).

The European Centre for Medium-Range Weather Forecasts said on Wednesday that an Atlantic Ocean heatwave reported in early July might have also influenced Europe’s current hot weather.

The Atlantic has seen a rise in temperature across most of its basins, especially in North America and Europe. Ocean heatwaves can affect atmospheric circulation patterns and warm the air masses above them.

Scientists say climate change, primarily triggered by greenhouse gas emissions mainly from burning fossil fuels, will result in more frequent, severe and dangerous heatwaves.

“Climate change across the globe is increasing the frequency, intensity and duration of heatwaves,” Akshay Deoras, a research scientist at the National Centre for Atmospheric Science at the University of Reading, told Al Jazeera.

“It’s effectively making heatwaves into severe heatwaves.”

What are anticyclones?

Cyclones bring stormy weather, and anticyclones are the opposite. They are high-pressure zones in which winds move slower. As a result, they are typically associated with clear, warm weather, but they also have the potential to turn into heat traps.

“If a high pressure comes in our region, and if it just moves away in a couple of days, then you don’t get that much heating because that’s just a transient phenomenon. But if it stays longer, then the temperatures go up,” Deoras said.

“That’s what happened last week. There was this high-pressure region that came from North Africa and anchored itself over Southern Europe. Then it went away, and we got another [one] this week, which they called the Charon new heatwave,” he added.

Hannah Cloke, a climate scientist also at the University of Reading, described what the phenomenon feels like.

“The bubble of hot air that has inflated over Southern Europe has turned Italy and surrounding countries into a giant pizza oven,” she said in a statement.

“The hot air, which pushed in from Africa, is now staying put with settled high-pressure conditions meaning that heat in warm sea, land and air continues to build,” Cloke explained.

Which countries have been most affected?

Greece, Italy and Spain are among the countries most impacted by the heatwave; however, parts of France, Germany and Poland also faced major heatwaves.

How long will the heatwave last?

According to the European Centre for Medium-Range Weather Forecasts, the extreme temperatures are expected to last until this Thursday before a less warm air mass moves in from the north. However, the relief might not last long as another period of extreme heat is expected at the beginning of next week (Sunday through Tuesday).

If the heat dome is not disrupted, the centre says it is possible that Europe could keep experiencing more episodes of extreme heat.

🌡️☀️Europe is experiencing some of the hottest conditions of summer 2023 so far, with some areas seeing temperatures above 45°C.
Our latest blog explores some of the causes & impacts of this #heatwave & what we expect to happen during the rest of summer.➡️ https://t.co/ISNXp4EBWO pic.twitter.com/LDjxfyf59f

— ECMWF (@ECMWF) July 19, 2023

What’s expected in the following days in Southern Europe?

In Greece, temperatures are expected to hit 41-45C (105-113F) in the coming days. The culture ministry said all archaeological sites, including the Acropolis in Athens, will be closed from noon to 5:30pm (09:00 to 14:30 GMT) until Sunday.

In Italy, high temperatures are expected in the country’s centre and south with 40C (104F) peaks in Sardinia and 41C (105F) in Palermo. However, Charon is expected to weaken in the north, bringing a break from the heat.

Some areas in Spain will also experience some relief. Storms are expected in northeastern Spain while the western Canary Islands will see strong gusts of wind. However, the southern cities of Seville and Cordoba are expected to register temperatures hitting 38C (110F) on Sunday.