A dense fog advisory will be in effect from now until 10 p.m. this evening, according to a National Weather Service report.
The advisory is in effect for mountains in Riverside County, San Bernardino County and San Diego County, as well as the mountains and foothills in Santa Ana.
A moist air mass is set to make its way to the coastal mountain slopes this evening, causing dense fog in areas throughout Southern California.
Later in the evening, a cold and dry air mass will make its way into the area, the report said.
Visibility will be limited to near zero at some points during the evening, according to the report.
The report said that the lack of visibility could negatively affect travel on Interstate 15 through the Cajon Pass and Interstate 8 through the San Diego County Mountains.
Visibility will be reduced to less than one quarter mile, so drivers should plan accordingly by using low beam headlights and giving themselves additional time to get to their destination, the report said.