Watch for Thin Ice on Lakes and Rivers...Here Are Some Safety Tips

Since record highs in the 70s occurred earlier in November, temperatures have been much colder.  Because of this, people perceive ice must be safe enough to venture out on if it has been in place for a week or two.  This is a myth!  

You can’t judge the strength of ice just by its appearance, age, thickness, temperature, or whether or not the ice is covered with snow. Strength is based on all these factors -- plus the depth of water under the ice, size of the water body, water chemistry and currents, the distribution of the load on the ice, and local climatic conditions.  There is no such thing as 100% safe ice.

The Wisconsin Department of Natural Resources issued a list of safety tips one should think about before attempting to venture out onto ice:

* Clear, solid ice at least two inches thick is usually sufficient to hold a single person walking on foot.  For safety's sake, wait until the ice is at least three inches thick and go with a friend.  Keep at least 50 feet distance between each other.  Ice fishing with several friends and gear requires at least four inches of ice, and snowmobiles and ATV's require five inches.

* Ice will generally be thicker near shore and get thinner as one ventures out further.  Check ice thickness with an ice spud or auger starting from a few feet from shore and every 10 to 20 feet as one goes towards the middle of the waterway. 

* Lake ice is generally stronger than river ice.  Springs, lake inlets and outlets, and channels can alter ice thickness. 

* Before heading out onto early or newly formed ice, check with a local bait shop, resort owner, or outdoors store regarding ice thickness or known thin spots.

* Whether alone or with a friend on early ice, always carry a couple of large sharpened nails and a length of rope in an easily accessible pocket.  The nails or commercially bought ice grabbers can help a person pull themselves out of the water and onto more solid ice.  The rope can be thrown to another person for rescue.

* Proper clothing can increase chances of survival should a person break through the ice.  A snowmobile type suit, if it is zipped, can and will trap air and slow the body's heat loss.  Once filled with water, however, insulated suits become very heavy and will hinder rescue.  Newer model snowmobile suits have flotation material built in and anyone traversing ice should consider purchasing one of these suits.  On early ice it is advised to wear a personal flotation device.

* Refrain from driving on ice whenever possible.  Traveling in a vehicle, especially early or late in the season, is a disaster waiting to happen!

* When driving on ice, be prepared to leave the vehicle in a hurry.  Unbuckle the seatbelt and have a simple plan of action in case of ice break through.  Anglers may want to leave a window open for an easy exit. 

* Often vehicles will establish roads from shore to the current fishing hotspots.  Repeated vehicle use may cause ice to weaken.  The ice roads may not be the safest routes.

* When using a gas or liquid heater to warm an ice shack or tent, make sure it is properly ventilated with at least two openings, one at the top and one at the bottom of the structure.  Any flame eats oxygen so proper ventilation is required.

Here are some additional tips:

* Keep children from playing on the ice without adult supervision.  Each year, it seems too many children drown or die of hypothermia due to reasons that are easily prevented.

* The National Weather Service does not measure ice thickness.  Because conditions are always changing, the level of danger associated with ice is always changing.  It is YOUR responsibility to make sure ice is sufficiently safe before enjoying Wisconsin winter outdoor activities.

Some ice thicknesses for new, clear ice that are considered safe for the following activities:

* 2 inches or less...STAY OFF

* 4 inches...Ice fishing and other activities on foot

* 5 inches...Snowmobile or ATV use

* 8 to 12 inches...Car or small pickup use

* 12 to 15 inches...Medium truck use

Additional information about ice safety can be found at the Minnesota Department of Natural Resources ice safety website located at:


Bill Borghoff

National Weather Service Milwaukee, WI

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