A prolonged and intense heatwave has killed at least 25 people across the eastern United States, with record-breaking temperatures shattering century-old records and placing more than 140 million people under active heat alerts over the Independence Day holiday weekend.
New Jersey bore the brunt of the crisis, with state authorities attributing at least 22 deaths across 10 counties to the extreme heat — the majority in the state's central and northern regions. Many of the victims were found in homes without air conditioning, on the street, or in parked cars. The deaths affected people ranging in age from their mid-30s to their 80s, and began occurring as early as Thursday. Governor Mikie Sherrill described it as "the hottest stretch we've seen in over 14 years," adding that the heat was affecting "people of all ages" — not just the elderly or those with underlying conditions. Beyond New Jersey, a resident of Cook County, Illinois, died with heat stress listed as a contributing factor, and in Hinds County, Mississippi, 74-year-old Mitchell Ray Cooley was found dead behind a gas station after going missing; his death was attributed to heat exposure. Also in Mississippi, 83-year-old Martha Irene Van Egmond died after falling in her garden and being unable to get up, spending hours in the heat before help arrived.
The cause of the extreme conditions is a heat dome — a meteorological phenomenon in which high atmospheric pressure traps hot air over a region, much like a lid holding steam inside a pot. Temperatures smashed longstanding records across the region: Newark, New Jersey, reached 105°F (40.5°C), while LaGuardia Airport in New York recorded 104°F (40°C), surpassing a record set in 1966. Atlantic City, New Jersey, hit 106°F (41.1°C) by Saturday. The multi-day nature of the event made it especially dangerous, as overnight temperatures failed to drop enough for the body to recover. In Washington DC, where holiday celebrations were disrupted, emergency services treated 51 people for heat-related illness on Saturday alone.
As the heat dome began shifting southward into the mid-Atlantic and southeastern states by Sunday, it gave way to severe thunderstorms across the midwest and northeast, knocking out power to roughly 900,000 homes and businesses, with particularly widespread outages in Michigan and Pennsylvania. Meteorologists warned of flash flooding risks for parts of Ohio, Pennsylvania, New Jersey, and New York as the storm system moved east.
Scientists and public health officials stressed that the event is consistent with the broader pattern of climate change, which is making heatwaves more frequent, longer, and more intense. "This is not a typical summer heatwave," New Jersey's department of public health stated. "This type of heat can quickly become life-threatening to humans and to animals of all ages." The National Weather Service urged residents to stay hydrated, avoid direct sun, seek air-conditioned spaces, and check on neighbours and relatives. Cooler air from the north was expected to bring some relief to the worst-affected areas in the coming days.