More than 60,000 customers in the Philadelphia area remained without electrical power Thursday as additional out-of-state repair crews arrived to help regional utilities recover from Tropical Storm Isaias.

Peco reported that 26,000 customers were still powerless, less than 10% of the 425,000 it says were impacted by Isaias. Most of the customers were in hard-hit Chester and Bucks Counties. Peco earlier reported that outages peaked at 307,000 during the storm, but revised its total to include all customers who lost power at some point during the event.

Public Service Electric & Gas, which has 2.3 million customers in New Jersey, said Thursday it had restored power to 475,000 of the 575,000 customers who lost it. About 11,000 customers in South Jersey are among the 100,000 still without power.

PSE&G said that Isaias was the fifth-most-severe storm in its history and the second most severe, to Hurricane Sandy, in the last eight years. It said it expected to have at least 85% of the outages restored by Friday night.

Peco, which has 1.6 million customers in Philadelphia and surrounding Southeastern Pennsylvania counties, said it expected to have 95% of outages restored Thursday. But some more troublesome outages will take longer to repair, and the company has told some customers not to expect their power to be restored before Sunday.

Some customers have been surprised after Peco restored power ahead of schedule.

Rick Newman, who fussed Wednesday night with a borrowed generator at his home on Roberts Avenue in Drexel Hill, said Peco restored power Thursday afternoon to the 22 houses knocked out on his block when an uprooted tree took out a power line. The lights came back on three days earlier than the Sunday target initially set by the utility.

“I have to say, I’m really impressed by that,” Newman said. He and other neighbors had complained on social media about the duration of the outage because one of their neighbors without power is on home hospice care.

Peco said it anticipates almost 2,000 additional field employees and contractors to be available to support restoration efforts. Crews from Illinois, Indiana, Ohio, West Virginia, North Carolina, and as far away as Texas are traveling to Southeastern Pennsylvania to assist.

Atlantic City Electric, which said that nearly 40% of its 525,000 customers lost power during the storm, has restored power to all but 23,000 customers Thursday. It expected that all customers, including those in the most heavily damaged areas, will have their service restored by Saturday night.

“We know that an extended outage is frustrating for our customers, and is even more challenging during this difficult time,” Gary Stockbridge, region president of Atlantic City Electric, said in a statement.