From the Midwest to the East Coast, a dangerous heat wave is spreading across more than half of the United States, raising the risk of record-breaking temperatures during the Fourth of July weekend – one of the country’s busiest holiday periods.
Local officials are responding by opening cooling centers, adjusting public events and expanding emergency services as crowds gather for fireworks, festivals and Independence Day celebrations.
Nearly 160 million Americans will be affected as a scorching heat dome stretches across 30 states through the end of the week, according to the National Weather Service.
The heat is being driven by the heat dome, a high-pressure system that traps hot air over a region for several days. High humidity is also increasing health risks, as it makes it more difficult for the human body to cool down through sweating.
In New York City, officials are opening outdoor misting stations and deploying mobile cooling vans to provide water, sunscreen and wellness checks.
“These are extremely dangerous conditions,” New York City Mayor Zohran Mamdani said in a news briefing. Temperatures in the city could exceed 100 degrees Fahrenheit on Thursday and Friday, with the heat index expected to be even higher.
Hot weather causes about 500 premature deaths in New York City each summer on average, according to city data.
Extreme heat in Philadelphia is forcing the National Constitution Center’s celebration of Pope Leo XIV on Friday indoors. The city has also reduced the operating hours for its World Cup fan festival ahead of Saturday’s match between Paraguay and France.
Washington, DC, has activated an extreme heat alert through July 5, as hundreds of thousands of visitors are expected to attend holiday events in the US capital. The temperature is forecast to reach 101 degrees Fahrenheit (38.3 degrees Celsius) on Saturday exceeding the city’s record for the date of 100 degrees set in 1919.
Many other places, including Boston, Massachusetts, and Raleigh, North Carolina, are also opening cooling centers and expanding public health resources.
The heat wave comes as the western United States faces heightened wildfire risks. Dry conditions and strong winds have fueled wildfires in Utah and southern Colorado.
About 2 million people were under fire alerts on Monday in the Four Corners states of Arizona, Colorado, New Mexico and Utah, as well as parts of Wyoming, South Dakota and Nebraska, NBC News reported.
Dozens of large fires were burning across the United States, scorching more than 580,000 acres (2,347 sq km), according to the National Interagency Coordination Center.
Dangerous heat wave threatens US Fourth of July celebrations
