(CNN) — Nearly a million acres were burning as 21 wildfires raged in the Pacific Northwest on Sunday, fire officials said.

The unconfined fires in Oregon and Washington, mostly ignited by lightning from thunderstorms that swept through the region a week ago, covered 942,247 by Sunday, Northwest Interagency Coordination Center spokeswoman Carol Connolly said.

The 21 large fires are the most the region has seen on the landscape at one time, she said.

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