Air-quality readings at 10 a.m. Tuesday.

Jackson County Public Health extended its air quality advisory through Wednesday as intermittent smoke from wildfires upwind of the Rogue Valley continues to billow into Southern Oregon.

And depending on weather and fire activity, the air quality could be impacted for longer.

Portions of Jackson County, including Medford, White City and Central Point, reached red or “unhealthy” levels Tuesday morning, while readings were “unhealthy for sensitive groups” in other parts of the Interstate 5 corridor going from west Medford to Talent, according to the Iqair.com website.

The Oregon Department of Environmental Quality states that the intermittent smoke impacting Jackson, Josephine, Deschutes, eastern Lane and northern Lake counties are due to smoke from the Diamond Complex Fire. Jackson County Public Health attributes the smoke to wildfires in Douglas County.