A vast “heat dome” over the July 4 weekend has subjected much of the US to record and near‑record temperatures; killing dozens of people, straining the power grid and exposing the stark class divide between who is protected and who cannot escape the suffocating conditions.

Beginning in late June and intensifying from July 1 through July 5, a severe heat wave spread from across the Midwest and South into the Northeast, putting roughly 180–200 million people under major or extreme heat alerts.

The National Weather Service reported, forecast and observed highs widely between 100° and 110° Fahrenheit across the central and eastern US, with peak heat indices (“feels like”) temperatures up to 115° degrees in some areas.

On July 2, ambient temperatures in New York City exceeded 100° F for the first time since 2012, while Boston reached 100–101° F, setting daily records and marking only the 29th time the city has hit the century mark.

Washington, D.C. recorded a 102° F high on July 2, with heat indices forecast to reach around 113° F heading into the holiday, while cities such as Philadelphia and Nashville saw indices above 110° F. By July 4, Atlantic City, New Jersey tied its all‑time high with a temperature of 106° F, an indicator of the dangerous conditions along the Eastern Seaboard.

The heat wave disrupted daily life and holiday celebrations across multiple regions, with authorities canceling or postponing parades, concerts and fireworks as the country marked the 250th anniversary of the Declaration of Independence.

• In Philadelphia, a major parade commemorating America’s 250th birthday was canceled as temperatures topped 100° F.
• In Washington, D.C., Trump’s “Salute to America” event on July 4 went ahead under a brutal heat index above 110° F, leading to nearly 300 medical interactions on the National Mall, with dozens transported to hospitals.
• Public transit systems in the Northeast and Midwest, including Amtrak, SEPTA and New Jersey Transit, were forced to reduce speeds or cancel trains as tracks and equipment buckled under the extreme heat.

On Sunday, the Guardian reported, for example, that New Jersey reported 22 deaths across 10 counties in the central and northern part of the state. The Guardian report said, “Many of the individuals were found in homes with no air conditioning, outside their residences, on the street and in parked cars, according to officials.”

NBC News reported one heat-related death in Cook County, Illinois, where government spokesperson Natalia Derevyanny said the cause was organic cardiovascular disease with heat stress as a contributing factor.

An NBC News report noted that public‑health experts say, “such cases represent only the most visible tip of a much larger iceberg of excess deaths, including elderly people in poorly cooled homes, outdoor and warehouse workers, and homeless people whose conditions may never be fully documented.”

The July 4 heat wave exposed the unstable and antiquated condition of the US electric infrastructure, particularly in the eastern half of the country.

With about 160 million people in 30 states under extreme temperature alerts, the US Department of Energy declared an emergency for the PJM Interconnection, the largest regional grid, ordering measures to prevent blackouts and keep essential services running.

PJM forecast peak electricity demand of 166.3 gigawatts on July 4 week, likely surpassing its previous summer record of 165.6 GW set in 2006. Real‑time wholesale prices in PJM surged to over $1,600 per megawatt‑hour on the Monday evening of the heat wave, compared to less than $40 earlier that day, reflecting severe congestion and stress on high‑voltage lines.

The extreme temperatures have pushed demand for power to or near record levels, causing wholesale electricity prices—the prices utilities pay for power—to spike dramatically. In New England, spot wholesale electricity prices jumped more than 243 percent on Thursday. 

These spikes are directly tied to the heat wave. Widespread temperatures near or above 100° F from Boston to Washington, D.C. have driven a surge in air‑conditioning use and forced grid operators to call hot‑weather alerts and emergency measures.

In New York City, officials pleaded with residents to raise thermostats to 78° F, shut off unused electronics and delay running appliances, while more than 17,000 customers lost electricity at points during the heat wave, leaving thousands suddenly without cooling.

Severe thunderstorms and high winds associated with this week’s weather left hundreds of thousands of Michigan customers without power at times, particularly across metro Detroit and southern Michigan. Crews worked through the holiday period to restore power to DTE Energy and Consumers Energy which reported that the outages were widespread.

Dearborn News reported a 16-year-old boy was found dead inside a home in Melvindale, Michigan following the power outage. The teenager has been identified by family as Wael Hamzah Haidara. Relatives have said he was new to the United States and that he was likely unaware of the dangers of carbon monoxide after a generator was left running in the home’s basement. 

Meteorologists and climate scientists have pointed to a stationary high‑pressure system—a “heat dome”—as the immediate cause of the oppressive conditions, supercharged by long‑term capitalist induced global warming. CNN meteorologists described “a dangerous heat wave tightening its grip on the East Coast and straining the electric grid as people seek to cool off,” noting that many records were already falling by the start of July.

Ramanan Krishnamoorti, vice president of energy and innovation at the University of Houston, told ABC News that, “it’s going to really strain the grid,” predicting “peak demand that is going to be a record across different geographical areas” and warning that “everything is sort of stretched to the limit.”

Other experts emphasized that nighttime temperatures were remaining extraordinarily high, offering “little to no relief” and preventing both people and power plants from recovering, a hallmark of heat waves intensified by climate change.

Across the country, people have described unbearable conditions. In major cities, residents interviewed about grid conservation measures complained that setting air conditioners to 78° F still meant sweltering apartments, especially in older buildings with poor insulation and overcrowded units.

Emergency departments reported “extremely high rates” of heat‑related visits, especially in low‑income neighborhoods where outdoor work, cramped housing and lack of alternative cooling options are prevalent.

While air conditioning is nearly universal in the United States, millions remain exposed because they lack it entirely or cannot afford to run it. New experimental data from the US Census Bureau and the Energy Information Administration shows that about 93 percent of the country’s 127 million households had AC in 2023, leaving roughly 9 million households without any air conditioning.

Lack of AC is concentrated in certain regions and social layers. For example, only about 35 percent of households in San Francisco County reported having air conditioning, reflecting coastal climates, aging housing stock and high costs.

Renters, low‑income families and residents of older multi‑family buildings are much less likely to have central air; many rely on a single window unit or fans, or nothing at all, making prolonged triple‑digit heat especially dangerous.

Even among households with AC, high electricity prices during peak demand mean that many working‑class families must choose between cooling and other necessities, leaving them semi‑voluntarily exposed to dangerous heat.

The US heat wave follows, by about a week, an even more deadly episode of extreme heat in Europe, underscoring the global nature of the crisis. A late‑June heatwave across Western Europe pushed temperatures to near or above 40° C (104° F) and has already been linked to several thousand excess deaths.

Preliminary national figures indicate more than 4,000 additional deaths in countries such as France, Belgium, the Netherlands and Spain, with France alone recording around 2,025 excess deaths during the week beginning June 22. A scientific analysis cited by New Scientist estimated that the June 22–28 European heatwave killed approximately 20,390 people, including thousands in France, Spain, Germany and the UK.

The same planetary processes—rising greenhouse‑gas concentrations and warming oceans altering atmospheric circulation—are driving both the European and North American heat domes, with working class and poor populations on both continents paying the highest price.

Families in older, poorly insulated housing or without reliable AC, enduring nights where indoor temperatures never fall to safe levels are faced with soaring power bills when they try to cool their homes. Homeless people and undocumented workers, face heat‑related deaths that often go uncounted or are dismissed as individual misfortune rather than a systemic failure.

On the other side are the wealthy and well-off layers whose homes, cars and offices are equipped with advanced climate control systems, backup generators and private access to cooled spaces. Corporate headquarters, luxury condominiums and high‑end vehicles maintain near‑constant temperature and humidity, turning the heat wave into a mere inconvenience while poorer layers queue at overwhelmed cooling centers or crowd into public libraries and malls for relief.