Dense fog advisory: what it means and what to do
“A Dense Fog Advisory is issued by your local National Weather Service office when widespread dense fog develops. When this happens, visibilities frequently drop to one-quarter of a mile or less. These conditions make travel difficult. Take extra caution when on the road or avoid driving if possible.”
weather.gov →Dense Fog Advisories in effect right now
No Dense Fog Advisories in effect right now.
National Weather Service data, updated Nov 2, 2026, 9:51 PM ET. Not an official warning: follow your local NWS office. All US alerts →
What to do now
- Slow down and allow extra time to reach your destination.
- Use your low-beam headlights, and fog lights if you have them. Never use high beams: they cause glare.
- Leave plenty of distance to the vehicle in front, and follow the lines on the road to stay in your lane.
- If visibility is near zero, turn on your hazard lights and pull into a safe place, such as a parking lot, and stop.
From the NWS fog driving safety tips.
Watch, warning or advisory?
Each in the National Weather Service's own words.
Dense Fog Advisory
“A Dense Fog Advisory is issued by your local National Weather Service office when widespread dense fog develops. When this happens, visibilities frequently drop to one-quarter of a mile or less. These conditions make travel difficult. Take extra caution when on the road or avoid driving if possible.”
Freezing Fog Advisory
“A Freezing Fog Advisory is issued by your local National Weather Service office when fog develops and surface temperatures are at or below freezing. The tiny liquid droplets in the fog can freeze instantly to any surface, including vehicles and road surfaces. Freezing fog makes driving, boating, flying and other forms of transportation particularly hazardous. Visibilities are typically at or below 1 mile.”
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