By Lauren Rosenthal and Ari Natter | Updated on Jun 12, 2026 at 03:52 PM
Dangerous heat and humidity will stress power grids along the US East Coast Friday, putting pressure on prices as the risk of severe thunderstorms spreads from the Midwest.
Temperatures are expected to spike above 100F (38C) from southern Virginia to North Carolina Friday, with sweltering humidity that makes the heat feel more intense. With cooling demand surging into the weekend, the Trump administration declared a power emergency in the southeastern US this week to shore up the grid.
An emergency order issued by the Energy Department on Thursday allows Duke Energy Corp. to operate power plants at their maximum output levels and exceed certain air pollution limits, as part of efforts to boost generation to meet soaring demand in North Carolina and South Carolina. The order is in effect through Friday night.
“The order will mitigate the risk of unnecessary blackouts brought on by unusually high-load forecasts and high temperatures across the region,” the Energy Department said in a statement.
The emergency order was requested by Duke earlier on Thursday, which said it expected unusually high power demand as homes and businesses cranked air conditioners throughout the Carolinas. This week’s heat comes on top of a severe drought across the area. The utility added it was concerned it may not have “sufficient generation” because of limits in its environmental permits and other conditions.
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The US Weather Prediction Center says strong-to-severe thunderstorms will be possible from the Mid-Atlantic to the Northeast on Friday as a cold front surges through the region. A wave of cooler air will help tame the heat somewhat Saturday, but temperatures may still surpass 90F along the East Coast.
Spot power prices on the grid operated by PJM Interconnection LLC, which spans the District of Columbia and 13 states from Illinois to New Jersey, surged past $1,400 per megawatt-hour late Thursday evening in a zone that includes Virginia’s “data center alley” and parts of North Carolina. Day-ahead prices in the region have peaked at $770 during the 3 p.m. hour Friday.