When extreme heat strikes France, Paris is rarely the hottest location, yet the capital has become a significant outlier regarding excess deaths during such events. During the heatwave of June 2026, public health authorities reported that the number of deaths in the Paris region doubled. While soaring temperatures were fatal across the entire country, the nationwide excess death figure was approximately 30 percent, highlighting that the capital suffered disproportionately.
This is particularly striking when examining weather maps, which often show that southern France experiences higher temperatures—sometimes topping 43C—and longer periods of extreme heat than the northern regions, where Paris temperatures repeatedly reached 40C.
The primary reason for this disparity is the city's "heat sink" effect. Like all major urban centers, Paris absorbs heat through its concrete surfaces and reflects it back, a process intensified by human activity, including vehicle emissions and the heat exhausted by air conditioning units.
Paris faces two specific geographic and environmental disadvantages: it suffers from a severe lack of green space and is situated in a hollow, which causes hot air to become trapped. Consequently, the city is regularly 10C hotter than the surrounding countryside during a heatwave.
A fundamental issue is that Paris was simply not designed for extreme heat. Cities in the south of France, such as Nice or Montpellier, experience similar or higher temperatures, yet the experience is more manageable because their urban design accounts for hot summers. These southern cities feature narrow, shady streets, buildings with thick walls, and small windows. In contrast, Paris was not built with these considerations because, until recently, the city did not experience such high temperatures.
Some aspects of its urban design were actually intended to keep heat inside rather than allowing it to escape. As the planet warms, even northern cities are now exposed to temperatures previously seen only along the Mediterranean coast.
Housing quality also plays a critical role in these fatalities. Much of the city's housing stock is extremely energy inefficient. Because the June death toll figures cover the greater Paris region, they include poorer suburbs characterized by poorly constructed modern tower blocks that effectively turn apartments into furnaces. In these low-income areas, most residents are renters who cannot make major structural changes to their homes and often cannot afford to purchase or run air conditioning units.
Samira, a resident of Ris-Orangis in Essonne, shared her experience with the Guardian newspaper in June, stating that the blazing sun hits her windows all day, making it impossible to breathe. She described her home as an oven, noting that she can only use a fan for short bursts due to electricity costs, leaving her exhausted and struggling to protect her son from the heat.
Architectural features even in the wealthiest areas of the capital contribute to the danger. The city's iconic grey roofs are constructed from zinc, which is a very poor insulator. During the June heatwave, a video went viral showing a man cooking a crêpe on a zinc roof, illustrating the extreme temperatures these surfaces reach.
The reality is far less humorous for those living in top-floor apartments directly under these roofs, as they are four times more likely to die during a heatwave than those living on lower floors.
Furthermore, while offices in Paris often have air conditioning, the majority of homes, schools, and hospitals do not. Renters are typically left to hope their landlords will invest in cooling systems or must rely on expensive and inefficient portable units.
Finally, the impact of heatwaves is exacerbated by social inequality. While Paris has a younger-than-average demographic, the surrounding suburbs, particularly the département of Seine-Saint-Denis, face high rates of poverty and deprivation. Residents in these areas are more likely to live in unsafe housing, have less access to green spaces or swimming pools, perform outdoor labor, and suffer from chronic health conditions.
In response to these systemic challenges, the city of Paris conducted a series of emergency planning exercises in 2023 to simulate how the city would cope if temperatures reached 50C. From these exercises, a resilience plan has been developed, with ongoing work to plant more trees, create additional green spaces, adapt existing buildings, and improve the city's overall heatwave preparedness.
Although the soaring temperatures proved deadly all over the country, the nationwide excess death figure was about 30 percent, making Paris an outlier in terms of heat fatalities.
READ ALSO: Grass roofs and siestas: How Paris is preparing for the day temperatures hit 50C
