The prolonged heatwave has claimed at least 25 lives, with the majority of fatalities concentrated in New Jersey. In New York City, health authorities reported over 378 individuals required emergency room treatment for heat-related illnesses. On 4/7, the US national day, 18 temperature records were broken, particularly in Washington DC, Baltimore in Maryland, Raleigh in North Carolina, Norfolk in Virginia, and Atlantic City in New Jersey. The intense heat persisted on 5/7.

Approximately 40 million residents across the East Coast, Southeast, and Southwest US faced severe heat warnings. Temperatures on the East Coast are forecast to gradually decline this week, with highs typically ranging from 21°C to below 35°C.

A person cooling off with water from an open fire hydrant during the heatwave in West Chicago, Illinois, 2/7. Photo: AFP

In the Southwest, extreme heat watch warnings were active for parts of Arizona and California, including the cities of Phoenix and Tucson, from 7-9/7. This dangerous heat is anticipated to continue until mid-week, with daytime highs potentially reaching 46°C.

Hundreds of thousands in the Eastern US experienced power outages, according to PowerOutages, an online platform tracking real-time data. This included over 215,000 households in Michigan, 151,700 in Pennsylvania, and 94,200 in New Jersey.

Alongside the heat, thunderstorms on 4/7 generated wind gusts across the Central and Eastern US. The National Weather Service reported some of the strongest gusts, reaching 148 km/h in Norman, Oklahoma, and 140 km/h in Suffolk County, New York.

Americans watching the Sail 250 sailboat parade at Liberty State Park, New Jersey, 4/7. Photo: Reuters

On 5/7, scattered showers and thunderstorms impacted parts of the Central Plains, Southeast, and Mid-Atlantic regions, placing 25 million people under storm warnings. This area encompasses Philadelphia, Washington, Baltimore, and Arlington, Virginia. While some thunderstorms might not be severe, they still carried a risk of lightning strikes.

As of 6/7, approximately 34 million people from Delaware to Connecticut were under flood warnings, even as the risk of severe weather significantly decreased. Slow-moving storms carrying substantial moisture were expected to heighten the risk of localized flash floods, especially in the Mid-Atlantic region.

New York City Emergency Management warned residents to prepare for heavy rainfall from 5-7/7. Forecasts indicated rainfall could reach 7,6 cm, with intensity up to approximately 5 cm per hour. "Heavy rainfall could cause flooding across the city, affecting highways, streets, basements, and tunnels," the agency stated. Storms could deliver approximately 5 cm of rain per hour, escalating the risk of urban flash floods in cities such as Philadelphia, New York, and Hartford, Connecticut.

Hoang Lan (According to NBC News, AP)