Heatwave Expected to Sweep Across United States Ahead of Independence Day Weekend
The National Weather Service warns that a heat dome will bring temperatures of 95-105°F and high humidity to much of the U.S., affecting about 120 million people as the Fourth of July holiday begins.
A broad heat dome is set to move across the United States this week, bringing daytime highs of 95°F to 105°F (35°C-41°C) and humid conditions that could push heat indexes above 100°F (38°C). The National Weather Service said roughly 120 million Americans are under an extreme heat warning as the country heads into the Fourth of July holiday weekend. The system is expected to peak in the Midwest and Mississippi Valley by Thursday before shifting eastward into the Ohio Valley and the Atlantic seaboard over the weekend.
Officials have urged residents to limit outdoor activity, stay hydrated and seek air-conditioned spaces. New York City Mayor Zohran Mamdani activated a heat-emergency plan, opening hundreds of cooling centers on Wednesday. Detroit announced a dozen recreation facilities with air conditioning for residents, while Philadelphia is moving parts of its FIFA World Cup fan festival into cooled tents.
Temperatures in Canada are also expected to remain elevated, with Ontario possibly reaching 37°C (99°F). The heatwave follows a recent early-summer heat event in Europe that broke multiple temperature records.
