San Francisco, California — Patchy fog will develop across the San Francisco Bay Area early Tuesday morning, reducing visibility and slowing the commute between 5 a.m. and 9 a.m. across San Francisco, Oakland, Daly City, Berkeley, and South San Francisco.
According to the National Weather Service, fog is expected to form after 5 a.m. with the densest conditions developing between 6 a.m. and 9 a.m., particularly near the coast and bayside areas. Visibility may drop below 0.10 miles in localized spots.
The sudden drop in visibility will create hazardous driving conditions along US-101, I-280, and the Bay Bridge approaches. Low-lying areas and coastal corridors, including fog-prone stretches near Daly City and underpasses along city streets, may see rapid visibility loss within minutes.
This is part of a broader marine layer pattern along the California coast, where overnight cooling and moisture near the surface are producing early morning fog.
Drivers should slow down, use low-beam headlights, and allow extra time during the 6 a.m. to 9 a.m. peak window.
