Dangerous heat is expected to persist into the holiday weekend, driving up power prices and raising the risk of travel disruptions across rail, air and roads.
A prolonged stretch of extreme heat across the central and eastern U.S. is expected to continue into the Independence Day weekend, deepening pressure on power markets and transport during one of the busiest travel periods of the year. Temperatures of up to 105 degrees Fahrenheit are forecast, with the National Weather Service warning that high humidity will make conditions feel even hotter and increase the risk of heat-related illness, especially for vulnerable people and those without adequate cooling. The surge in air-conditioning demand has sent wholesale spot electricity prices sharply higher, including gains of more than 243% in New England and 101% in New York City on Thursday, according to U.S. Energy Information Administration data. Prices also rose nearly 55% in the Midwest and 45.6% in the Mid-Atlantic. Rail and air travel are also under strain: Amtrak said trains may need to run at reduced speeds and face delays between 11 a.m. and 7 p.m. through July 4 in the Northeast, Southeast and Midwest, New Jersey Transit warned of delays and cancellations on trains into New York, and Delta Air Lines said it would waive change fees for journeys through LaGuardia Airport this week because of the heat. The Illinois Department of Transportation also cautioned drivers about possible pavement buckling. New York City Mayor Zohran Mamdani urged residents to ease strain on the grid by setting air conditioning to 78 degrees, turning off unused electronics and shifting appliance use to early morning or late at night. The heat wave comes as scientists say climate change is increasing the frequency and intensity of extreme weather events.