July 6 (Reuters) - Data from PowerOutage.us showed that more than 623,000 homes and businesses were without power as of late Sunday due to severe weather conditions in several parts of the United States.

The data revealed that Pennsylvania was the most affected, recording approximately 119,300 power outages, representing about 1.8 percent of the state's total customers of 6.7 million.

The utility company most affected was a unit of PPL Electric Services in Pennsylvania, where power was cut off to approximately 79,945 homes and businesses.

PPL Electric Services said on its website, "We have restored power to more than 130,000 customers since the storm began, but there is still a lot of work to be done and crews are still repairing extensive damage and rebuilding parts of the electricity network."

Michigan had the second-highest number of power outages, affecting approximately 110,060 customers. The most affected utility in the region was a unit of DTE Energy, with approximately 82,183 outages.

DTE Energy said on its website, "We expect to restore power to 95 percent of affected customers by the end of Monday, July 6."

Con Edison, the New York-based energy company, said Sunday that it had restored power to more than 166,800 customers out of approximately 173,700 whose service was affected by the severe weather conditions.

The company added that the cities of Yonkers, Mount Vernon, Rye, and New Rochelle in Westchester County, north of New York City, experienced the largest number of storm-related outages, and that power was expected to be restored to 95 percent of customers affected by the storms on July 4 in Westchester by 7 p.m. EST (2300 GMT) on Monday.