More than half of the United States is sitting under a heat dome this holiday weekend, and forecasters say more than 300 records are expected to be set by Saturday.
Dangerously high temperatures stretched from the Midwest to the East Coast on Thursday. Temperatures are running 20 to 30 degrees above average in many locations. Some spots could shatter records that are more than a century old, according to CBS News meteorologist Nikki Nolan.
New York City tied its record high temperature for July 3 of 100 degrees, a mark first set in 1966. The city could hit triple digits again Friday, with the heat index climbing even higher. An extreme heat warning is in effect in New York until 9 p.m. Saturday.
"These are extremely dangerous conditions," Mayor Zohran Mamdani warned the city's more than 8 million residents.
For the first time, New York City deployed vans staffed with nurses and paramedics to hand out water, electrolytes, and sunscreen. Those teams will also perform wellness checks, transport people to cooling centers, and make in-home visits to vulnerable residents. The city opened cooling centers across all five boroughs.
"My recommendation to all New Yorkers is to stay inside and stay cool," Mamdani said.
Boston hit 100 degrees Thursday, reaching that mark for the 29th time in its recorded history and setting a new daily high temperature record for the date. An extreme heat warning is in effect in Boston until 8 p.m. Saturday.
In Washington, D.C., the National Weather Service issued an extreme heat watch with forecast highs of 103 degrees. An extreme heat warning there is also in effect until 8 p.m. Saturday.
Nashville could see temperatures reach 101 degrees and feel like 114. Heat patrols there began handing out cold bottled water to the city's homeless population during peak hours.
In Philadelphia, organizers shortened the city's Salute to Independence parade on Friday because of the heat. An extreme heat warning is in effect in Philadelphia until 8 p.m. Saturday.
A high of 101 is forecast for Saturday, July Fourth itself, which would top existing records for that date in several locations.
