A line of gray haze settled over the Valley Thursday morning after storms Wednesday night - and with little wind in the forecast, it may stay there for a while.
With the dust and high ozone levels, the Valley is under a high pollution advisory through Friday for both PM-10 and ozone.
Maricopa County Air Quality Department spokeswoman Holly Ward said her department fielded several calls Thursday morning as people drove into Phoenix and took a look at the sky, which looked like the aftermath of a fire.
The Arizona Department of Environmental Quality issued the high pollution advisory as numbers of air quality monitors came in from across the Valley. A high pollution advisory is posted when PM-10 or ozone levels are expected to rise above federal standards.
Pinal County took the brunt of the storm Wednesday night, but PM-10 - tiny specks of dust that can aggravate the lungs - were elevated as far away as the west Phoenix monitor, Ward said.
Ozone is an invisible gas created when other pollutants in the air are heated by the sun. The Valley remains under an excessive heat warning Thursday, with temperatures that could reach 111.