It’s December, the weather is colder and that means a lot of hard water anglers are getting the “bug” to be out on the surface of a lake. While there has been some ice on area lakes, it is not time yet! It just hasn’t been cold enough, long enough, to have a good layer of ice form on our lakes.
How thick does ice have to be to be safe? Ask that question to five different people and you’ll get at least four different answers. Personally, I prefer to have a minimum of about six inches of ice before I start feeling comfortable on the ice by myself. My philosophy on ice fishing: more is better. I have punched through the ice a couple of times and I’ll tell you that it is not my favorite way to have fun!
According to a Nebraska Game and Parks Commission web article, it takes at least three inches of clear, blue lake ice to support a single angler. At five inches of ice, you can have several anglers standing on the ice, but not grouped around the same hole. They go on to say eight inches of ice will support a snowmobile.
To show you how much variance there is in “predicting” safe ice thicknesses, on a U.S. Army Corps of Engineers website, I found a table saying that two inches of ice will hold a single person on foot. Three inches would hold a straight line of anglers close together or a snowmobile and seven inches will support a small pickup truck. As I said earlier, with ice fishing, thicker ice is better. I’m thinking some Corps of Engineers flunky in Florida put together that ice safety table.
The Minnesota Department of Natural Resources has what I consider to be much more believable data on a section on their website. For new, clear ice only, it suggest the following:
- 2 inches or less -- stay off
- 4 inches -- ice fishing or other activities on foot
- 5 inches -- snowmobile or ATV
- 8 to 12 inches -- car or small pickup
- 12 to 15 inches -- medium truck
Remember that these thicknesses are merely guidelines for new, clear, solid ice. Many factors other than thickness can cause ice to be unsafe. 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, the size of the body of water, water chemistry and currents, the distribution of the load on the ice and local climate conditions.
As you can see, the recommendations for “safe ice” can vary greatly. I’d go with the Minnesota suggestions. They have people there who really do a lot of ice fishing!
Another term you hear when talking about ice is the type of ice that has formed. For example, blue ice is considered good ice. But what is blue ice? The term “blue ice” originated with arctic explorers for use in defining glacial ice. Blue ice is the ice that results from snowfall, after snowfall and the lower layers get compressed by the weight of the snow above it. It appears very clear because all the air bubbles have been squeezed out of it.
On a lake, the “blue ice” forms when there are extremely cold temperatures and little wind. The ice molecules are large in this kind of ice development, and by being larger, they are stronger. The blue color comes from the ability of the ice to scatter and diffuse light. To the human eye, it looks blue.
Most of the ice we see formed on Nebraska waters would fit more into the category of gray ice. The gray color comes from thousands of tiny air bubbles being trapped in the ice. These air bubbles, even though they are quite small, represent voids or openings in the ice. This means that it is not a solid sheet of ice and can be weaker.
Here are a few other considerations when determining whether ice is safe to venture out on:
- Steady, sub-freezing temperatures: the colder it is, for a longer period of time, results in a better freeze up of lake waters.
- Calm days and nights: the less the wind blows, the faster and more solid ice freezes.
- Heavy snows or rain can hinder the formation of good ice.
- Vegetation: shoreline plants generally result in thinner ice. Avoid these areas when possible.
- Location-specific factors: if there are springs, feeder creeks or aquifers that put water into the lake, make sure you know where those areas are to avoid weak ice.
- Moving water causes thinner ice. If there is current under the ice, be very cautious.