Is there a heatwave in Europe?

Yes. Southern Europe’s heatwave, which is affecting the region on July 21, 2023, is being caused by a high-pressure anticyclone (1)(2). An anticyclone is a weather event where winds move in a large circular pattern around an area with high atmospheric pressure. This anticyclone, along with another weather system named Charon, has anchored itself over Southern Europe, leading to extreme temperatures in parts of Greece, eastern Spain, Sardinia, and Sicily in southern Italy.

The heatwave is characterized by a "heat dome," which is a high-pressure circulation in the atmosphere that acts like a lid, trapping hot air in place and creating vast areas of sweltering heat.

The extreme heat in Europe is additionally exacerbated by climate change and the ongoing climate emergency, which is increasing the frequency, intensity, and duration of heatwaves across the globe.

This extreme weather has also resulted in hail in northern Italy (3). The United States and China area also experiencing severe heatwaves.

How will the heat wave affect air quality?

Rising temperatures can result in greater ozoneproduction, a pollutant that is the main ingredient in smog. A heat wave can also fuel intense, long-lasting wildfires. Wildfire smoke can greatly harm short-term and long-term heart and lung function.

Which cities or areas are affected by the heatwave?

The heatwave is impacting several cities, towns, and regions in Southern Europe. Some of the affected areas include:

• Athens, Greece: The Acropolis of Athens and other archaeological sites in Greece have announced reduced opening hours due to the heatwave conditions. Wildfires have also threatened outskirts of the city.
• Rome, Italy: The government has issued red alerts for 16 cities in Italy due to the current heatwave, including Rome. Temperatures in the center and south of the country are expected to record peaks close to 40 degrees Celsius (104 degrees Fahrenheit).
• Madrid, Spain: The city is facing another heatwave, and extreme heat is likely to abate in most of Spain during the last week of July.

Portugal, the Balkans, and parts of Germany, France, and Poland are all likely to experience elevated heat as well.

How long will the heatwave in Europe last?

According to the European Centre for Medium-Range Weather Forecasts (ECMWF), the extreme temperatures are expected to last until Thursday. However, a slightly less warm air mass from the north is set to provide some respite from the heat from Thursday onwards.

Nevertheless, this relief may be short-lived, as another period of extreme heat is forecast for the end of the current week and the beginning of the next week (Sunday through Tuesday). If the heat dome is not disrupted, Europe could continue experiencing more episodes of extreme heat in the future.

Are there any alerts in place?

Yes, there are alerts in place due to the heatwave and related wildfires.

In Italy, extreme heat red alerts have been issued for 23 cities, indicating that the heat is so intense it poses a risk to the entire population.

In Greece, where wildfires have been causing damage, Greek Prime Minister Kyriakos Mitsotakis has warned of the need for "absolute vigilance and absolute readiness" in the face of the ongoing heatwave and the potential strengthening of winds. As a precautionary measure, the Greek Culture Ministry has closed all archaeological sites and monuments, including the Acropolis in Athens, each afternoon through to Sunday. These measures are crucial for the safety of residents and visitors in the affected areas.

How can I protect myself from wildfire smoke and extreme heat?

Always plan ahead to protect yourself from wildfire smoke.

• Get a free air quality app for real-time air quality alerts and forecasts.
• Shut doors and windows and set the HVAC to recirculate mode.
• Run a high-performance air purifier to filter wildfire smoke.
• Contribute to your community’s outdoor air quality data.
• Stay indoors; if you do need to go outdoors, wear a KN95/FFP2 mask.

To protect yourself during extreme heat:

• Drink plenty of water throughout the day, even if you don't feel thirsty. Avoid alcohol, caffeine, and sugary drinks.
• Seek out air-conditioned places like shopping malls, libraries, or community centers. If you don't have access to air conditioning, spend time in shaded areas or use fans to circulate air.
• Dress to stay cool.
• Avoid going outside. If you must go outside, use sun protection, limit physical activity, and avoid peak heat hours.
• Take cool showers or baths.
• Check on vulnerable individuals.
• Never leave children or pets in vehicles.