North Bay Interior Valleys under Dense Fog Advisory until Friday Morning
On Friday, the National Weather Service (NWS) in San Francisco, CA, issued a dense fog advisory for the North Bay Interior Valleys. This advisory is in effect until 10 a.m.
Fog Conditions and Visibility
The NWS warns of visibility reduced to one quarter of a mile or less in dense fog. Such low visibility can create hazardous driving conditions.
"Low visibility could make driving conditions hazardous," said the NWS. "If driving, slow down, use your headlights, and leave plenty of distance ahead of you."
Safety Recommendations for Drivers
- Drive slowly and cautiously.
- Use headlights to improve visibility.
- Maintain a safe distance from the vehicle ahead.
- Avoid driving if possible until the fog clears.
A dense fog advisory is issued when widespread fog reduces visibility to one-quarter of a mile or less, which can significantly complicate travel.
This story was originally published November 7, 2025, at 1:52 AM.
Source
National Weather Service
Summary: A dense fog advisory affecting North Bay Interior Valleys warns of dangerously low visibility until 10 a.m., urging drivers to take extra precautions during travel.