How Thick Does Ice Need to Be to Walk On

When temperatures plummet, ice can form quickly, bringing out people who love and are drawn to activities on ice, from skating to fishing, and on average, it only takes about four days of below-freezing temperatures for small ponds and lakes to freeze over. How Thick Does Ice Need to Be to Walk On?

As a general rule of thumb, ice is safe to walk on when there is 4 inches or more of clear ice. It is important to understand that different types of ice vary in their strength. Clear blue or black ice is the strongest.

  • 2 inches or less-Stay Off
  • 4 inches or more-Ice skating or other activities on foot

The ice on lakes and ponds is typically thicker in the middle than at its edges due to the water depth because near shore, where the water’s surface meets land, there are physical limitations to how much ice can be present. There are many variables to how safe ice is, so before you go out on the ice this winter, read this article.


Ice Color


It’s good to remember that the color of the ice is directly related to how safe it is. If the ice is grey or greyish, beware of it, and don’t step out onto it.

If the ice is any shade of grey, it is likely decaying or melting, and it is probably fairly thin and weak. The source of the grey color is typically the dark liquid water underneath, showing through the ice. Even if it is very light or pale grey, it is best to err on the side of caution.

  • The color of the ice may be an indication of its strength.
  • Clear blue ice is the strongest.
  • White opaque or snow ice is half as strong as blue ice. Opaque ice is formed by wet snow freezing on the ice. It’s about 1/2 the strength of Clear ice.
  • Grey ice is unsafe. The grayness indicates the presence of water.


How Thick Does Ice Need to be to Skate On


As a general rule of thumb, ice is safe to walk on when there is 4 inches or more of clear ice. It is important to understand that different types of ice vary in their strength. Clear blue or black ice is the strongest.

Every year people from around the world who have cold season temperatures take to the frozen lakes, rivers, and ponds for the sport of ice skating and hockey.

At least 15 centimeters thick for a person to walk or skate on it, 20 cm thick for a group of people, and at least 25 cm thick for snowmobiling.

If the ice is not marked as safe, then you must know how to judge whether or not it can be walked on or ice-skated on. One way to make certain the ice is thick enough is to drill down into the ice to take direct measurements.

This is may the fastest way and the one that involves the least amount of guessing. There’s one problem, though, you need to walk out onto the ice to do this.

So, you could be putting yourself in danger if the ice isn’t thick enough to support your weight. Anything under 4 inches should be avoided. Even if it is above 3 inches, you should have safety gear or know how to get out of the water if you fall through the ice.

You may be able to skate on thinner layers down to as little as 5 centimeters and 2 inches in thickness, but only if the ice is virgin black. Always be aware of any hazardous conditions that you may find, like frozen objects sticking out from under the ice and dark patches with weak spots. Always partner up to skate or play hockey.

At 4”, the ice is good enough for popular activities such as ice fishing, cross-country skiing, and walking and can support more than 200 pounds. At 5 inches of new clear ice should be enough to hold a snowmobile or an ATV that weighs 800 pounds.

Changing temperatures can happen in the winter when warm sunny temperatures can cause freezing and thawing conditions which will create very slippery, slick ice that’s very easy to fall on. 

In this video, the ice thickness is measured here with an ice climber’s screw to confirm safe depth.



How Thick Does Ice Need to be to Drive On


If you ignore the thickness of the ice, your winter activities could end horribly. Be careful and know the limitations.

At least 9 inches thick in the ice can support a car driving on the ice.  But if there are multiple cars, then there is multiple weight. Then 9 inches may not support the weight leading to a disaster.

At 30 inches of ice-that would be enough to support a 20,000 lb. semi-truck or 10 tons of weight, much like the trucks used on the Ice Road Truckers TV show. If you watched the show, when there are spots on the ice that is less than that, the truck could fall through.

When you do have multiple cars or trucks on the ice, to be safe, keep them 50 ft. apart from each other and move them every 2 hours or so. Snowmobiles typically weigh around 1000 pounds and need around 5 inches of ice to support them. The average UTV weighs about 1,500 pounds without passengers or gear. If you’re taking it on the ice, look for at least 8 – 9 of ice.

  • 8-12 inches: Car or small pickup
  • 12-15 inches: Medium truck

How to Measure Ice Thickness


After a week or so, small ponds and lakes freeze over but are they safe to walk on? The best way to be sure is to measure the thickness yourself if the ice isn’t posted by the township or county in whatever state you are in.

In this video, the ice is in a remote spot on a river in Alaska, and a battery-operated drill with an auger attachment is used.

  • Use an Ice Chisel or Spud 
  • An Ice Auger-hand, gas, or electric is the most common way of measuring
  • Cordless Drill: A cordless drill with 18″ wood-auger bit-Tape measurements on the auger 4-6-8-15
  • Ice Screw: designed for use in ice climbing

Remember, thickness is only one consideration while enjoying activities on ice, and the minimum thicknesses should be guidelines only.  Local conditions and the type of water body will affect the ice strength.

Check with local authorities for information on local ice conditions before heading out on the ice. If you are alone and do go through the ice, Watch this video on How to perform a self Rescue.



According to the Red Cross: Most importantly, you should obey posted signs indicating when and where the ice surface is acceptable for certain activities.

Avoid going out on the ice at night. Many factors affect ice thickness, including the type of water, location, the time of year, and other environmental factors such as:

  • Water depth and size of the body of water.
  • Currents, tides, and other moving water.
  • Chemicals, including salt.
  • Fluctuations in water levels.
  • Logs, rocks, and docks absorb heat from the sun.
  • Changing air temperature.
  • Shock waves from vehicles traveling on the ice



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JimGalloway Author/Editor


References: Red Cross– Ice Saftey

Ausable River Association
Ice Saftey

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