Heavy fog was reported in some areas of Tampa Bay early Friday, but the worse of it seems to have cleared, said Bay News 9 meteorologist Brian McClure.
In central Pinellas, visibility was limited to about 100 feet early Friday. Areas in Hernando, Hillsborough and Pasco were also affected.
The denser fog was pushed away by dry, cool air moving into the region, McClure said, but some patchy fog will remain until sunrise.
The National Weather Service warned drivers of foggy conditions early Friday along the coast of southwest Florida.
Visibility will remain between 2 to 5 miles, with some areas dropping down to a quarter mile, the weather service said.
Drivers were advised to slow down, use low beam headlights and allow extra time for commuting.