WASHINGTON — A prolonged and dangerous heat wave continued to grip large parts of the central and eastern United States on Monday, prompting health warnings, straining power systems and emergency services, and leaving officials urging residents to limit outdoor activity as extreme temperatures and humidity persisted across the region.
The National Weather Service (NWS) said widespread areas from the Midwest and Mississippi Valley through parts of the Ohio Valley, Mid-Atlantic and Northeast remained under heat-related alerts after several consecutive days of exceptionally hot weather. Forecasters warned that heat index values — a measure combining temperature and humidity — could reach as high as 115 degrees Fahrenheit (46 degrees Celsius) in some locations, while overnight temperatures were expected to remain unusually warm, reducing opportunities for relief.
Officials across affected states continued to advise people to stay hydrated, seek air-conditioned spaces, avoid strenuous outdoor activities during the hottest parts of the day, and check on older adults, young children and other vulnerable residents. Cooling centers remained open in numerous communities as local governments sought to reduce the health impacts of the extended heat.
The extreme weather has been linked to a persistent high-pressure system, commonly known as a heat dome, which has trapped hot, humid air over much of the region. The NWS also warned that the same atmospheric pattern could trigger severe thunderstorms in some areas, bringing risks including damaging winds, large hail and localized flash flooding as cooler air interacts with the hot and unstable air mass.
In New Jersey, authorities said at least 19 deaths were suspected to be heat-related during the prolonged hot spell, although investigations into individual cases were continuing. State officials said many victims were found in homes without air conditioning or outdoors during periods of extreme heat, underscoring the dangers posed by sustained high temperatures.
Utilities also faced elevated electricity demand as millions of households and businesses relied heavily on air conditioning. In some areas, severe thunderstorms accompanying the weather pattern caused power outages after damaging trees and power lines, complicating recovery efforts.
Forecasters said temperatures were expected to ease gradually in parts of the Northeast as the weather system shifted eastward, although dangerous heat was forecast to persist across portions of the South and lower Mississippi Valley. The National Weather Service said additional heat advisories and warnings could remain in effect where hazardous conditions continued.
