Weather Explainers

What Is Black Ice And Why Is It So Dangerous?

At a Glance

Black ice is a thin coat of highly transparent ice.
It can lead to hazardous driving conditions.

Black ice can be very dangerous, so it's important to know what it is and how you should react if you have an encounter.

The most basic definition of black ice is a thin coat of highly transparent ice. The reason it is transparent is because it blends in with road pavements since it is so thin, making it nearly impossible to see. It's called black ice since it looks black, like the color of the road pavement it forms on.

(MORE: When is the Coldest Time of the Year?)

This is an example of black ice on a dark roadway.
(Getty Images)

What Causes Black Ice?

If the temperature rises above freezing or the sun comes out during the day, any snow on the ground will slowly melt and cause road surfaces to become wet. If it rains, that could also lead to wet roadways with some puddles.

If the temperature then drops below freezing while the ground is still wet, black ice will likely form on paved surfaces due to the refreezing.

(MAPS: Current Temperatures)

Black ice can also form if moisture in the air condenses and forms dew or fog, and then the temperature drops below freezing.

These are common locations where you may find black ice.

Common locations to find black ice include bridges, overpasses and spots on the road shaded by trees or other objects.

Bridges and overpasses are prone to black ice because cold air is able to flow underneath the road surface, since it is elevated, therefore lowering the pavement temperature. Shaded spots on the road are prone since they receive less warmth from the sun during the day.

(MAPS: 10-Day Forecast High and Low Temperatures)

Why Is Black Ice So Dangerous?

Since black ice is highly transparent, it is unlikely you'll be able to see it while driving down the road.

Roadways become very slippery when black ice forms, leading to hazardous driving conditions and an increased risk of car accidents.

(MORE: Weather-Related Car Accidents Far More Deadly Than Tornadoes, Hurricanes, Floods)

Here are a few tips that may help if you get caught in areas of black ice:

Keep your steering wheel straight. If you turn the wheel, you have a better chance of sliding and losing control of your vehicle.
Do not brake. Braking causes the vehicle to slide, especially if you brake too hard.
Take your foot off the accelerator to reduce speed. It is best to let the car stop on its own if you have enough room in front of you.

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