Millions of Americans across the Midwest, Northeast and swathes of the South and Southwest have been are under air quality alerts Monday after smoke from multiple wildfires blanketed much of the U.S.

Smoke from a wildfire in San Luis Obispo and Santa Barbara counties is affecting air quality to start the week in Los Angeles. The Gifford Fire was estimated Monday morning at more than 65,000 acres. The fire started Friday in Los Padres National Forest. Containment was at 3 percent.