A prolonged and dangerous period of extreme heat across the central and eastern U.S. is poised to continue into the Independence Day weekend, exposing pressure points for power markets and transport.
Temperatures of up to 105 degrees Fahrenheit (40.5 degrees Celsius) are expected, according to the National Weather Service, with some daily, monthly and all-time records possible.
The conditions can bring increased risk for heat-related illness, particularly for vulnerable populations and those without adequate cooling, the NWS said.
The heat wave threatens to overwhelm U.S. grids and may force some to cancel, postpone or otherwise change their plans on one of the busiest travel weeks of the year.
How the heat wave is straining power grids
Wholesale spot electricity prices jumped more than 243% in New England and 101% in New York City on Thursday, according to data from the U.S. Energy Information Administration. Power prices also rose by nearly 55% in the Midwest and 45.6% in the Mid-Atlantic.
The surge in electricity prices comes as demand soars for air conditioning, with the NWS warning that very high humidity will make the heat wave feel even hotter.
New York City Mayor Zohran Mamdani urged residents on Thursday to help alleviate the strain on the state's energy grid, asking them to set their air conditioning to 78 degrees Fahrenheit, turn off electronics not in use and wait until the early morning or late at night to run appliances like dishwashers or laundry machines.
Mamdani also called on New Yorkers to stay inside to avoid the worst of the heat and responded to a question about the widely reported wedding of Taylor Swift and Travis Kelce planned for Madison Square Garden.
"My recommendation to all New Yorkers is to stay inside and stay cool, and if you happen to be getting married at Madison Square Garden, you will be staying inside and you will be staying cool, and I think it is a good example to set to the city at large," Mamdani told reporters.
The heat wave comes as scientists warn that climate change is exacerbating the frequency and intensity of extreme weather events. The burning of fossil fuels such as coal, oil and gas is the chief driver of the climate crisis.
Travel delays expected during July 4 week
Rail authorities have warned of the potential for delays through the weekend.
Amtrak said earlier in the week that trains may need to operate at reduced speeds and could experience delays between the hours of 11 a.m. and 7 p.m. through July 4 due to the forecasted extreme temperatures in the Northeast, Southeast and Midwest.
New Jersey Transit trains into New York were also expected to face delays and cancellations due to the heat-related impact on equipment.
Delta Airlines, meanwhile, issued a service notice earlier in the week saying it will waive change fees for journeys through New York's LaGuardia Airport this week due to the hot weather.
The Illinois Department of Transportation warned drivers to be mindful of pavement failures, saying surfaces could buckle in the extreme heat.
