A prolonged and deadly heatwave sweeping across Europe has taken a devastating toll on Athens, where 175 people lost their lives during a recent ten-day period of extreme temperatures. According to a rapid study published by the Grantham Institute – Climate Change and the Environment at Imperial College London, the heatwave that struck between 23 June and 2 July resulted in 2,300 deaths across 12 European cities.
The findings highlight the deadly impact of climate change, with 1,500 of the deaths – roughly 65% – directly linked to global warming, which has raised average temperatures by 1°C to 4°C. The report describes heatwaves as a growing “silent killer” on the continent.
People jump into the Drim river to cool off from hot weather in Struga, North Macedonia July 20, 2025. REUTERS/Ognen Teofilovski
Climate Change as a Deadly Factor
The study estimates that without the current levels of climate disruption, many of the deaths would likely not have occurred. In cities such as Milan (317 deaths), Barcelona (286), Paris (235), London (171), Rome (164), Madrid (108), and Athens (96), climate change was found to be a contributing factor in a significant share of the heat-related fatalities.
In fact, the death toll from this single heatwave has exceeded that of some recent natural disasters, such as last year’s floods in Valencia, which resulted in 224 deaths.
The elderly are disproportionately affected, with 88% of climate-related heat deaths occurring among those aged 65 and older, underlining their vulnerability.
Greece Faces Prolonged Heat
As July progresses, Greece remains gripped by persistent, extreme heat. According to meteorologists, temperatures are expected to reach 44–45°C in parts of the country on Tuesday and Wednesday. The heatwave, driven by hot air masses from North Africa, is forecast to begin easing by Saturday.
“This is shaping up to be an unusually extreme heat episode,” said Kostas Lagouvardos, Research Director at the National Observatory of Athens and coordinator of the METEO weather service. “It may not break temperature records, but the duration and intensity are rare, with widespread temperatures above 40°C and high nighttime heat, especially in large urban areas.”
A person lies under an umbrella on the beach, as a heatwave hits Europe, in Ostend, Belgium July 18, 2025. REUTERS/Yves Herman
He emphasized that each consecutive day of high temperatures compounds the health risk, and the oppressive conditions are expected to persist through Thursday and Friday. “What concerns us most is the persistence of these heatwaves in recent years,” Lagouvardos added, noting that major heatwaves occurred in 2021, 2023, 2024, and again in 2025, with only 2022 offering a brief reprieve. “It could be coincidence, but it may also signal that the climate crisis is no longer a future threat — it is already here.”
Notably, June 2025 was the second-warmest June on record, and July is already tracking 1.5°C above normal. These trends reinforce the pattern of escalating summer temperatures in Greece and southeastern Europe.
Nea Paralia, Thessaloniki, Greece on July 8, 2025. / Νέα Παραλία Θεσσαλονίκη, 8 Ιουλίου 2025.
Where It’s Hottest
According to the National Meteorological Service, the hottest areas are expected to be central and northern mainland regions, such as Thessaly, Central Macedonia, and Central Greece. Meteorologist Theodoros Kolydas warned that temperatures could locally hit 45°C, with at least five consecutive days of extreme heat across the country.
Island regions will fare slightly better, with maximum temperatures expected to be 3–4°C lower due to coastal breezes. However, major urban centers will continue to experience high heat and discomfort, particularly during the night.
August Forecast and Public Health Alert
Looking ahead, August is expected to be warmer than average across southeastern Europe, including Greece. Climate forecasts suggest a 35% to 38% probability of temperatures being 1°C to 2°C above normal, and a 23% chance of even higher anomalies.
A thermometer displays the temperature on a hot day, in Rovaniemi, Finland, July 15, 2025. REUTERS/Alexander Kuznetsov
In response to the ongoing crisis, the Crisis and Risk Management Committee of the University of Athens issued an urgent public warning. Vulnerable groups — especially older adults, infants, people with chronic illnesses, and outdoor workers — are advised to take extra precautions.
Health professionals, public agencies, and the broader community are being urged to increase awareness, educate the public, and coordinate responses to safeguard those most at risk.
As climate change continues to fuel increasingly dangerous heatwaves, the message from experts is clear: this is not an isolated summer — it may be the new norm.
