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Dense fog blankets downtown Milwaukee
A dense fog advisory was issued for several southeast Wisconsin counties on Tuesday morning. FOX6's Rob Haswell explains how it happened.
MILWAUKEE - The National Weather Service issued a dense fog advisory for most of southeast Wisconsin until 9 a.m. Tuesday. The fog could drastically lower visibility when driving – here's what to know.
What is fog?
What we know:
According to the National Weather Service, clouds and fog both form when water vapor condenses or freezes to form tiny droplets or crystals in the air, but clouds can form at many different altitudes while fog only forms near the ground.
Thick fog over Milwaukee on October 20, 2026
Brights Lights
On a vehicle:
When visibility is low and it is dark, the natural human instinct is to add light so we can see! You might turn the bright lights in a room at night or, in this case, on your vehicle. However, notice in the photo below that turning the bright lights on in a car still makes it challenging to see. Why?
Driving in fog with bright lights. (Credit: Lisa Michaels)
Normal and bright lights are mounted higher on the vehicle. This light has a high-beam that shines forward which goes towards the fog—the tiny water droplets. The light then bounces off of the water droplets and reflects towards the driver, making it appear brighter and more difficult to see. So you do not want to use bright lights in this scenario, but there is a better option—fog lights!
Fog Lights
On a vehicle:
Fog lights are mounted low on the front of the vehicle to ‘cut through' fog’. This light has a low-beam that shines near the ground to go under the water droplets. This helps illuminate the ground, roads, and road markers. Notice that in this photo below, you can more easily define the roads and lines, making it easier and safer to drive.
Driving in fog with fog headlights (Credit: Lisa Michaels)
Not all vehicles have fog lights, but it can be extremely beneficial when hazardous driving conditions are present.
Driving Tips
What you can do:
There are various additional driving safety tips to take other than just using fog lights when low visibility is present: reduce your driving speed since visibility distance can change rapidly, and it is very important to leave more space between you and other vehicles to prevent an accident.
It is also important to pay attention to the forecast prior to heading out the door to prepare for when fog can and will form.
The Source: Information in this story is provided by the National Weather Service and the FOX6 Weather Experts.