Red, White and Sweltering: Heat Wave Disrupts Fourth of July Celebrations

A dangerous heat wave disrupted Fourth of July celebrations across the central and eastern United States.

Dozens of parades, concerts, and fireworks were canceled or postponed.

In Washington, the Great American State Fair on the National Mall, a centerpiece of President Donald Trump's 250th anniversary events, closed temporarily as temperatures hit 101°F (38°C), according to Reuters.

Washington's Signature Parade Canceled

The National Park Service canceled its Independence Day Parade, scheduled for 10:30 a.m. ET Saturday, citing safety concerns as the Weather Service projected heat index values up to 115°F.

The extreme heat stemmed from a "heat dome" high-pressure system that spread record temperatures from the Midwest to the East Coast this week.

Cancellations Spread Across the Region

More than 185 million people, over half the U.S. population, were under heat alerts, with peak heat indexes reaching 115°F (46°C) in parts of the country.

Philadelphia canceled its Salute to Independence Parade after temperatures hit 103°F on Thursday, tying a record from 1901.

Haddon Township, New Jersey, called off its parade; Watertown, New York, canceled its concert and fireworks; and Boston delayed its riverside fireworks by four hours, to 4 p.m.