A severe heatwave swept across the central and eastern United States on Friday, forcing the cancellation of dozens of Independence Day parades, concerts, and fireworks displays and placing more than 185 million people under extreme-heat alerts, according to the National Weather Service. The capital, Washington, saw the annual National Independence Day Parade called off late in the evening, while the Great American State Fair on the National Mall — a centrepiece of the 250th anniversary programme — was temporarily closed as temperatures reached 38°C. In Philadelphia, authorities cancelled the Salute to Independence Parade after the city matched a 1901 record of nearly 40°C the previous day. The heat, driven by a high-pressure “heat dome” that trapped hot, humid air over the region, pushed peak heat-index values to a forecast 46°C in several locations.

Health and infrastructure systems came under immediate strain. Medical sources in Washington reported that at least eleven people were taken to hospital from the fair with heat-related illnesses before the site was cleared. In New York, the utility Con Edison said roughly 17,000 customers were without power by late Friday afternoon, while the PJM grid operator — serving 67 million people in the mid-Atlantic and South — ordered emergency conservation measures to cope with generator outages and surging air-conditioning demand. City authorities in New York converted hundreds of public buildings into cooling centres and dispatched volunteers to check on vulnerable residents, as Mayor Zohran Mamdani described the conditions as “extremely dangerous.”

Despite the widespread disruption, the official “Salute to America” programme promoted by President Donald Trump’s administration was maintained. Organisers said the evening fireworks display, military flyovers, and a presidential address would proceed, though visitors were advised to arrive later in the day. The heatwave also cast uncertainty over weekend World Cup matches, with the France–Paraguay fixture in Philadelphia expected to be played in extreme conditions. Climate researchers, cited in Indonesian and British press reports, noted that while such a heatwave remains rare — with an estimated frequency of once every 200 years — it would be virtually impossible without the 1.4°C of global warming caused by fossil-fuel emissions.

Forecasters warned that the danger would persist through Saturday, with overnight temperatures offering little relief. The National Weather Service cautioned that the risk of heat illness remained “high” to “extreme” for millions, particularly for those without access to adequate cooling. No new date has been set for the cancelled Washington parade, and officials across the eastern seaboard continued to monitor the strain on power grids as the holiday weekend unfolded.