A brutal heat wave tests the city's defences

A punishing heat wave gripped New York City this July, pushing temperatures into the mid-90s and beyond for days on end, straining the power grid and sending residents in search of relief in cooling centres, pools and the shade of the city's parks.

The oppressive heat, part of a broader pattern of extreme temperatures across the country and the world, posed particular dangers in a dense city of concrete and asphalt, where the "urban heat island" effect can make temperatures feel even higher and where many residents, especially the elderly, lack air conditioning.

City officials issued heat advisories, opened hundreds of cooling centres and urged New Yorkers to check on vulnerable neighbours. The utility Con Edison asked customers to conserve energy to prevent strain on a grid pushed to its limits by surging demand for air conditioning, and some neighbourhoods experienced scattered outages.

Heat is among the deadliest weather hazards, and officials stressed the risks of heat-related illness, particularly for the elderly and those with health conditions. Advocates pointed to the uneven burden of extreme heat, which falls hardest on lower-income communities with less tree cover and fewer resources.

The heat wave was a reminder that rising temperatures driven by climate change pose a growing threat to cities, and it renewed calls to expand access to cooling, plant more trees and harden the grid against a hotter future.