The heat is on

AUSTIN (KXAN) — A Dense Fog Advisory is in effect until 9 a.m. for Fayette Co. Visibility reports from Lee and Fayette Cos. were under one mile at 6 a.m.More dense fogToday is an Ozone Action Day for Williamson, Travis, Hays, Caldwell, and Bastrop counties. A sunny sky, the forecast of hot temperatures and light winds out of the south will lead to ozone levels on the lower end of the "Unhealthy for Sensitive Groups" range on the south side of Austin.An Ozone Action Day in the Austin Metro