An air quality alert is in effect for 23 metro Atlanta counties until 8:45 p.m. tonight, warning that the air outside may be unhealthy for some people.

What’s happening: The alert is rated Code Orange, which means air quality is likely to be unhealthy for people who are sensitive to it. Ozone levels are expected to peak during the late afternoon and early evening hours.

Who should be careful: Children, people with heart or lung disease, and anyone who is sensitive to ozone should stay inside or cut short any outdoor activity this afternoon and evening.

Counties covered: The alert includes Bartow, Barrow, Carroll, Cherokee, Clayton, Cobb, Coweta, Dawson, DeKalb, Douglas, Fayette, Forsyth, Gwinnett, Hall, Henry, Newton, North Fulton, Paulding, Pike, Rockdale, South Fulton, Spalding and Walton counties.

The path forward: The alert expires tonight. For ongoing air quality information, visit airnow.gov.