Record-setting heat wave blamed for 22 deaths across eastern U.S.

Record-setting heat killed 22 people across the Deep South, Midwest and East Coast, turning the Fourth of July weekend and America’s 250th anniversary celebrations into a public-health emergency. Nearly 156 million people in the eastern two-thirds of the country were under heat alerts on Saturday, and more than 185 million were covered by alerts on Friday.

The National Weather Service warned that heat index values could reach 100 to 115 degrees in parts of the region, with warm overnight lows offering little relief. More than 300 daily temperature records were projected to fall by Saturday, adding to a holiday weekend that was expected to rank among the hottest on record in some places.

In Washington, D.C., where Salute to America 250 events drew crowds to the National Mall, emergency workers and National Guard members helped attendees suffering heat-related ailments. The District’s Extreme Heat Alert remained in effect from Wednesday, July 1, through Sunday, July 5, and Mayor Muriel Bowser urged residents and visitors to plan ahead and limit time outdoors. Some festivities were delayed after severe thunderstorms prompted officials to urge people to seek shelter.

The weather also pushed city leaders and transit operators to change plans far beyond the capital. Cities across the eastern and central United States altered or postponed July Fourth events, and Amtrak canceled some Northeast trains because of the heat’s effects on tracks. At the same time, the U.S. Department of Energy issued two emergency orders to help stabilize the Mid-Atlantic grid ahead of predicted record-breaking peak loads, as utilities braced for heavy demand.

Storms compounded the crisis. More than 72 million people were under severe thunderstorm watches on Saturday, and PowerOutage.us showed power outages affecting more than 900,000 utility customers across a diagonal stretch from Arkansas to Michigan to New York, among other states.