A sprawling heat wave combined with afternoon thunderstorms swept across the eastern United States on July 3, 2026, leaving tens of thousands of customers without power as extreme temperatures strained electrical grids from Michigan to Virginia. More than 14,000 Michigan residents lost power as of 8:30 a.m. on Friday, while over 3,500 outages struck Roanoke and Franklin County, Virginia, and additional power outages affected customers across New Jersey, New York, Massachusetts, Tennessee, and other states.
The power outage crisis unfolded amid a dangerous heat dome affecting more than 160 million people across 30 states, with actual temperatures climbing into the 90s and lower 100s and heat index values exceeding 110 degrees in major cities. New York City hit 100 degrees, Washington, D.C., reached 100 degrees with a heat index of 111, and Philadelphia recorded 100 degrees with a heat index of 111, according to CNN.
The extreme heat triggered record electricity demand that forced emergency intervention from federal authorities. The U.S. Department of Energy issued emergency orders for PJM Interconnection, the nation’s largest electrical grid operator serving the mid-Atlantic region, with orders taking effect late June 30 and remaining in force through July 3. PJM had forecast peak electricity demand of approximately 166,304 megawatts on July 2, which would exceed the existing summer record, according to ElectricChoice.
In New York City’s metro area, more than 6,000 customers lost power as of 2 p.m. on Friday, July 3, largely due to the sustained heat wave, Con Edison spokesperson Jamie McShane told CNN. The utility company had already restored service to more than 60,000 customers affected by scattered outages since the heat wave began, but voltage reductions remained in effect across parts of Staten Island, Queens, the Bronx, Brooklyn, and Westchester. Mayor Zohran Mamdani urged residents to set air conditioning to 78 degrees and unplug appliances to help reduce the load on the grid.
Thunderstorms developed along the northern edge of the heat dome on Friday afternoon and evening, creating another spike in power outages. The New York Times reported that the heat also put stress on power grids, contributing to scattered outages in New Jersey, New York, and Ohio for tens of thousands of utility customers. Storms capable of producing gusty winds, heavy rain, and frequent lightning threatened to knock out additional power across the Midwest and Great Lakes region, according to UPI.
Earlier in the week, as of July 1, more than 100,000 customers were without power nationwide, down from more than 167,000 outages reported Tuesday night, according to UPI. AccuWeather meteorologists warned that the combination of extreme heat, surging air conditioning demand, and rounds of thunderstorms could quickly push outage totals higher. “The extreme heat and humidity are expected to bring near-record, or possibly record, energy usage to the mid-Atlantic power providers,” AccuWeather senior meteorologist Alan Reppert said. “This is especially critical on Thursday, as some companies could see possible power cuts to stabilize the grid if it becomes unstable.”
The federal Department of Energy authorized PJM to dispatch specified power units and activate backup generation resources as a last resort before or during the most serious level of grid emergency. The agency noted that more than 35 gigawatts of unused backup generation remained available nationwide to help manage the crisis.
Power outages during extreme heat pose acute health risks, especially for older adults, young children, people with chronic health conditions, and those without access to cooling centers. Warm nighttime temperatures prevent homes from cooling down after sunset, compounding the danger. Multiple cities, including Boston, New York, Philadelphia, Washington, D.C., and Raleigh, North Carolina, opened or expanded cooling centers and deployed mobile medical vans to provide water, sunscreen, and wellness checks during the holiday weekend.
Sources
- UPI — heat wave power grid concerns, outages exceeding 70,000 nationwide as of July 1, DOE emergency orders for mid-Atlantic, storms threatening additional outages
- CNN — more than 6,000 New York metro customers without power July 3, voltage reductions in effect, Con Edison restoration efforts, storm impacts
- Detroit Free Press — more than 14,000 Michigan residents without power as of 8:30 a.m. July 3
- WDBJ7 — more than 3,500 power outages in Roanoke and Franklin County, Virginia on July 3
- ElectricChoice.com — PJM emergency orders effective July 1-3, forecast peak demand of 166,304 MW on July 2
- The New York Times — scattered outages in New Jersey, New York, and Ohio due to heat stress on power grids
- Marblehead Current — power restored to approximately 1,000 customers in Marblehead, Massachusetts after heat-wave outage
