(Reuters) - Over 713,000 homes and businesses in Texas, Kentucky and other states were without power on Tuesday as storms continued to batter the region since the long Memorial Day holiday weekend, according to meteorologists and data from PowerOutage.us.

That is down from more than 939,000 customer outages earlier on Tuesday.

Tornado-spawning thunderstorms that swept the Southern Plains and the Ozark Mountains killed at least 21 people across four U.S. states over the long Memorial Day weekend.

Texas power company Oncor, a unit of California-based energy company Sempra Energy, has the most outages with over 397,000 customers without power in the Dallas-Fort Worth area, according to PowerOutage.us.

Oncor said it was assessing damages, making repairs and restoring outages caused by storms producing hail, rain and destructive winds, including wind gusts as high as 95 miles per hour (153 km per hour) in the Dallas-Fort Worth area and surrounding areas.

"The damages caused to our facilities is extensive and restoration will likely take multiple days," Oncor added on its website.

Major outages by state:

State Outages

Texas 636,907

Kentucky 33,172

Arkansas 25,807

Missouri 9,106

California 8,514

Total Out 713,506

(Reporting by Scott DiSavino and Sherin Elizabeth Varghese; Editing by Aurora Ellis and Christopher Cushing)