UPDATE 1-Heat wave disrupts Fourth of July events across eastern US

A dangerous heat wave upended Fourth of July celebrations ‌across swaths of the central and eastern U.S. on Friday (July 4, 2026), ​forcing officials in the nation’s capital and elsewhere to ⁠cancel or postpone dozens of parades, concerts and fireworks displays.

Among the events disrupted by the sweltering heat was the Great American State Fair on ‌the National Mall in Washington, a centerpiece of President Donald Trump’s efforts to mark the nation’s 250th birthday. The ‌fair was temporarily closed on Friday afternoon (July 3) as temperatures reached ‌101 ⁠degrees Fahrenheit (38 degrees Celsius).

Organisers said they expected it ⁠to reopen at 5 p.m. local time, with modifications like cooling tents and misting stations.

Record-breaking temperatures spread to the eastern U.S. from the Midwest earlier this week due ​to the emergence of a high-pressure ‌system known as a “heat dome,” which traps a mass of hot air over a region and can cause humidity to spike.

Over 185 million people, more than half the U.S. ‌population, were under heat alerts on Friday (July 3, 2026), the National Weather ​Service said. Peak heat indexes could reach 115 F (46 C) in parts of the country.

Forecasters and government officials ⁠have warned that the heat wave could prove deadly. They urged Americans celebrating the Fourth of July weekend outdoors to stay hydrated, ‌seek shade and watch for signs of heat illness at gatherings and public events.

Event cancellations were reported across the Eastern Seaboard for the July 4 weekend, when Americans typically gather for barbecues, parades and fireworks displays to celebrate the nation’s 1776 Declaration of Independence from Britain.

In Philadelphia, officials canceled the Salute to ‌Independence Parade, a marquee event in the city’s semiquincentennial celebrations, citing extreme heat. The ​decision came after temperatures hit 103 F on Thursday (July 2), tying a record high last seen in 1901.

Elsewhere, heat-related disruptions ⁠rippled across the region. Haddon Township, New Jersey, canceled its annual ⁠July 4 parade, while Watertown in upstate New York called off its Independence Day concert and fireworks display.

In ‌Boston, officials delayed entry to an annual riverside fireworks celebration by four hours, to 4 p.m. instead of noon.