Heat dome to bring another day of stifling temperatures ahead of much-needed relief

Heat dome to produce another hot, humid day across eastern US before much-needed relief

Tens of millions of people in the eastern half of the U.S. will need to deal with one more day of extreme heat before some much-needed relief arrives. FOX Weather Meteorologist Craig Herrera breaks down the forecast on June 25, 2025.

NEW YORK – A massive heat dome that sparked the first major heat wave of the summer brought record-breaking temperatures to cities from the Midwest to the Northeast this week, but some much-needed relief from the extreme weather is on the horizon.

Officials across the eastern half of the U.S. urged people to prepare and take precautions to prevent heat-related illnesses as temperatures skyrocketed. Still, it wasn’t only the heat that proved to be dangerous.

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NEW YORK, NY - JUNE 24: A man cools off in the water amid high temperatures at Washington Square on June 24, 2025 in New York City. Tens of millions of people in major cities across the U.S. Northeast are facing record high temperatures on Tuesday on what was expected to be the worst day of an oppressive heat wave that has spread over much of the country since late last week. (Photo by Liao Pan/China News Service/VCG via Getty Images)

(Getty Images)

On Monday, a group of 20 people, including children, were cooling off in a South Carolina lake when they were suddenly struck by lightning as a thunderstorm swept through Lexington. 

It was also a dangerous day for firefighters in Massachusetts, who not only had to battle flames, but also the elements.

The Norfolk Police Department said a three-alarm fire broke out at a home on Main Street on Tuesday morning, and two firefighters needed to be taken to a local hospital to be treated for heat exhaustion.

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Watch: Water from fire hydrants help New Yorkers beat the heat

A video shared from Manhattan’s Washington Heights neighborhood shows children and adults running and jumping under water pouring from fire hydrants as New York City faced another day of scorching heat on June 24, 2025.

On Monday, 30 cities across the eastern half of the U.S. broke or tied century-old records, and another 11 cities did the same on Tuesday. Among the most notable records that were broken on Tuesday included Islip, New York, which reached 100 degrees. That makes it the third-hottest day on record for that location.

Plattsburgh, New York, tied its old record of 101 degrees, and Newark, New Jersey, hit 103 degrees, breaking its daily record and tying its monthly record. 

Boston soared to 102 degrees on Tuesday afternoon, and Philadelphia hit 101 degrees. That’s the first time Philadelphia has hit 100 degrees since July 18, 2012.

In total, the FOX Forecast Center said temperatures topped 100 degrees in 13 states, while records from North Carolina to Maine fell.

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Power grids strained as millions crank up the air conditioners

Power transmission lines during high temperatures in Columbia, South Carolina, US, on Tuesday, June 24, 2025. 

(Sam Wolfe/Bloomberg via Getty Images)

In the Southeast, the Department of Energy issued an emergency order amid surging power demand to help mitigate the risk of blackouts. The order authorized Duke Energy Carolina to utilize resources to operate at its maximum output levels in the extreme heat. 

"As electricity demand reaches its peak, Americans should not be forced to wonder if their power grid can support their homes and businesses," U.S. Secretary of Energy Chris Wright said. "Under President Trump’s leadership, the Department of Energy will use all tools available to maintain a reliable, affordable, and secure energy system for the American people. This order ensures Duke Energy Carolinas can supply its customers with consistent and reliable power throughout peak summer demand."

The emergency order remains in effect through Wednesday.

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Watch: Cows keep cool in North Carolina creek amid heat wave

A video shared from North Carolina shows some cows at the Feathered Farm in Zebulon trying to keep cool in a creek amid a heat wave on June 24, 2025. 

Shelters were opened in Middleborough, Massachusetts, on Tuesday, after a town-wide power outage plunged thousands of utility customers into darkness as temperatures soared.

Town officials said power went out late Tuesday afternoon, and the Nichols Middle School was opened for residents and their pets to seek safety from the extreme heat. Power was restored just before 9 p.m., but the town's library remained open until 11 p.m. for residents to stay cool.

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Power companies across the East Coast were urging customers to conserve energy as temperatures soared, but said they were prepared to respond to any outages.

Con Edison said crews worked around the clock in hot conditions to restore power to customers in the Bronx in New York City and even handed out dry ice to their customers.

Eversource also asked its customers in Massachusetts, Connecticut and New Hampshire to be aware of their energy usage.

"While high electricity usage during a heat wave can put a strain on the electric system, the energy company is prepared to meet the increased demand, and its crews are ready to respond to any outages or issues that may arise," the company said.

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Relief from stifling heat on the way

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Heat alerts remain in effect from the Midwest to New England, but many of the Extreme Heat Warnings – the most dire heat alert – have been reduced to Heat Advisories.

More than 102 million Americans remain under a Heat Advisory, while just over 25 million remain in an Extreme Heat Warning. This includes cities like Wilmington and Raleigh in North Carolina, Richmond in Virginia and Philadelphia and Pittsburgh in Pennsylvania.

Washington, New York City and Boston have been placed under a Heat Advisory.

Temperatures will once again get into the mid- to upper 90s on Wednesday along the Interstate 95 corridor on the East Coast, but relief is on the way.

New York City, for example, has a forecast high temperature of about 96 degrees on Wednesday afternoon, but on Thursday, the forecast high temperature is only expected to be about 80 degrees.

Friday will feel even cooler, with a forecast high of 68 degrees.

In the mid-Atlantic and Southeast, temperatures are expected to remain in the 90s for the rest of the workweek.