Extreme heat forecast: What to expect as heat wave hits Midwest, Northeast
A dangerous heat wave is bringing prolonged extreme heat to the Midwest, the South and the East Coast this week.
The heat started in the Midwest, where extreme humidity levels are rivaling the Amazon rainforest, creating life-threatening conditions for tens of millions of people.
Chicago activated cooling centers throughout the city, including at community service centers, senior centers, libraries, city colleges and police districts. Chicago Public Schools said all summer programming will be inside through Wednesday.
On Wednesday, the dangerous heat expands from the Midwest and the South into the Northeast.
The heat index -- what temperature it feels like with humidity -- is forecast to soar to 104 degrees in Chicago, 109 in Detroit, 104 in New York City, 107 in Philadelphia, 108 in Washington, D.C., and 111 in Nashville, Tennessee.
Amtrak warned that some trains may operate with reduced speeds Wednesday through Saturday due to the heat advisories in the Northeast, Southeast and Midwest. Amtrak noted that this could cause delays from 11 a.m. through 7 p.m. on those days.
By Thursday, the heat index could reach 106 degrees in Boston, a scorching 111 degrees in New York, 110 in Washington, D.C., and 109 in St. Louis, Missouri.
New York City has activated its heat emergency plan and is opening hundreds of cooling centers on Wednesday, including at the Javits Convention Center, schools and libraries, Mayor Zohran Mamdani said.
"I'm also asking every employer to plan ahead with their teams, build in flexibility, and make sure that no one is put at risk during their jobs this week," the mayor said on Tuesday.
There will be minimal relief overnight, which makes the heat even more dangerous.
The unrelenting heat will continue on Friday. The heat index is forecast to hit 107 degrees in New York, 110 in D.C., 105 in Raleigh, North Carolina, and 109 in Memphis, Tennessee.
It'll stay hot and humid on the 4th of July on Saturday, with triple digit heat indices across the Midwest, South and Northeast.
Extreme heat is considered the deadliest weather-related hazard in the U.S.
At least 13,000 Americans have died from heat since 2018, according to the Centers for Disease Control and Prevention.
Click here for tips on how to stay safe.
ABC News' Dan Peck and Michelle Simmons contributed to this report.
