Paris is experiencing a severe heatwave, with rooftop temperatures on the city’s iconic zinc mansard roofs reaching as high as 80 degrees Celsius (176 degrees Fahrenheit), according to Eytan Levi, founder of Roofscapes, a company focused on rooftop gardens. Forecasts predict daytime highs of up to 40 degrees Celsius (104 degrees Fahrenheit), intensifying concerns amid a stalled municipal response.

The city’s 19th-century architecture, largely designed under Baron Haussmann, was not built to cope with such extreme heat. More than 70% of Paris’s buildings feature Haussmannian façades protected by stringent heritage regulations overseen by France’s building architects’ authority and the culture ministry. These restrictions severely limit the installation of external air conditioning units, which are frequently denied permits to preserve the historical aesthetics. Paris has historically maintained an aversion to air conditioning, viewing it as culturally invasive.

Levi warned that the widespread prohibition of AC units leads residents to install them without authorization, exacerbating urban heat by expelling hot air outdoors, further raising ambient temperatures. He emphasized the urgency of green solutions, noting that covering zinc rooftops with vegetation could reduce roof temperatures from 80 degrees Celsius to around 36 degrees Celsius, helping lower indoor temperatures to approximately 30 degrees Celsius.

Past heatwaves have had dire consequences. The 2003 heatwave caused an estimated 14,800 excess deaths in France, with Paris’s infrastructure overwhelmed as many residents had left the city, leaving vulnerable populations exposed. Morgues ran out of capacity, requiring temporary refrigerated storage for bodies.

Experts warn that such heat events will only increase in frequency and severity. Alexandre Florentin, a climate engineer and former city councilor, projects that by 2050 temperatures could reach 50 degrees Celsius in Paris. Florentin highlights a lack of preparedness despite growing awareness, citing disruptions such as cancelled train services during recent heat spikes, diminishing options for residents seeking relief.

In 2023, Florentin and environmental specialist Maud Lelièvre co-authored a report outlining infrastructure vulnerabilities in Paris, including risks to railway tracks, steel bridges, and roadways from heat-induced expansion and melting. Although the French government has since unveiled a national climate plan comprising 52 measures, Lelièvre states the plan remains largely unfunded and unimplemented, with heatwaves still treated as isolated crises rather than recurring emergencies.

Lelièvre advocates for immediate, practical interventions such as increasing urban greenery and opening public air-conditioned spaces during heatwaves to protect residents. She warns against relying on air conditioning as a personal solution to a collective problem, describing it as an individualistic response to a structural crisis that will require 10 to 20 years to address comprehensively.

In response to recent heat, Paris authorities have allowed swimming in a restricted area of the Canal Saint-Martin and plan to open three sites along the Seine for swimming starting in July. Despite clear safety warnings, some young residents have been diving into the canal to escape the heat, risking injury amid polluted and potentially hazardous conditions.

As Paris endures record temperatures and regulatory challenges, the city grapples with balancing heritage preservation with urgent climate adaptation needs.