Here’s how long the dense fog is expected to last in the Fresno area for the night

A dense fog advisory has been issued Tuesday for much of the central San Joaquin Valley by the National Weather Service, lasting until midnight.

Visibility could be less than a quarter mile in some areas, and motorists are advised to slow down, use headlights and leave plenty of distance between vehicles.

The fog is expected to lift overnight, according to Meteorologist Jim Andersen with the NWS in Hanford, meaning school districts might not be on a foggy day schedule for Wednesday.

A weak system is moving into the Valley. But before it arrives, a thickening of fog occurs, Andersen explained. It’s temporary, only lasting a few hours.

The clouds, meanwhile, are not expected to drop much of anything on the Valley floor, except perhaps some drizzling Wednesday, Andersen said.

He added that Mariposa and parts of Merced counties could see rain showers.

The thick fog, along with the poor air quality, made Tuesday a rough day to be outside.