The fog caused delays for many people in the Valley Tuesday morning.
Drivers on Highways 99, 180 and 41 in Fresno faced a challenging commute as fog blanketed the area. Traffic on a few interchanges was heavier than usual.
Some people heading out of town ran into problems as well. At least one flight headed from Fresno to Denver had to be delayed due to the fog.
The foggy conditions also delayed classes for many schools. Almost 20 schools and districts called in foggy day schedules.