Dangerous heat dome grips 30 states as extreme temperatures disrupt Independence Day celebrations and heighten wildfire risks
WASHINGTON: A dangerous heatwave has gripped more than half of the United States, placing nearly 160 million people under extreme heat alerts as millions prepare to celebrate the Fourth of July with fireworks, festivals and outdoor gatherings.
The National Weather Service (NWS) has warned that a powerful heat dome covering around 30 states is expected to keep temperatures at dangerously high levels throughout the Independence Day weekend, increasing the risk of heat-related illnesses and setting the stage for potential record-breaking temperatures.
A heat dome is a high-pressure weather system that traps hot air over a region for several days. Combined with elevated humidity, the phenomenon makes it more difficult for the human body to cool itself through sweating, significantly raising the risk of heat exhaustion and heatstroke.
Cities activate emergency measures
Authorities across several major cities have implemented emergency measures to protect residents and visitors during one of the busiest travel weekends of the year.
In New York City, officials have opened cooling centres, installed outdoor misting stations and deployed mobile cooling vans to distribute drinking water, sunscreen and conduct welfare checks on vulnerable residents.
New York City Mayor Zohran Mamdani warned that temperatures could exceed 100°F (38°C) on Thursday and Friday, with the heat index making conditions feel even hotter.
According to city officials, extreme heat contributes to around 500 premature deaths in New York City each summer.
Holiday celebrations affected
The oppressive weather has forced organisers to modify several Independence Day events across the country.
In Philadelphia, celebrations at the National Constitution Center marking Pope Leo XIV have been moved indoors because of the intense heat. City officials have also reduced operating hours for the FIFA World Cup fan festival ahead of Saturday’s match between Paraguay and France.
Meanwhile, Washington, D.C. has declared an extreme heat emergency through July 5, as hundreds of thousands of visitors are expected to attend Fourth of July celebrations. Forecasters expect temperatures to reach 101°F (38.3°C) on Saturday, potentially surpassing the city’s previous July 4 record of 100°F, which has stood since 1919.
Other cities, including Boston and Raleigh, North Carolina, have expanded access to cooling centres and public health services to assist residents during the prolonged heatwave.
Wildfire danger intensifies
The extreme temperatures are also increasing wildfire risks across the western United States.
Dry vegetation, low humidity and gusty winds have fuelled active wildfires in Utah and southern Colorado, while nearly 2 million people remain under fire weather alerts across parts of Arizona, Colorado, New Mexico, Utah, Wyoming, South Dakota and Nebraska.
According to the National Interagency Coordination Center, dozens of large wildfires are currently burning nationwide, consuming more than 580,000 acres of land.
Weather authorities have urged residents to avoid strenuous outdoor activities during the hottest hours of the day, stay hydrated, check on old-age neighbours and relatives, and make use of cooling centres as the dangerous heatwave continues through the holiday weekend.