Tips from the Minnesota Department of Natural Resources and Mass. Wildlife:
While some lakes and ponds may develop a thick enough ice sheet after a few days of below freezing weather, each body of water is different and it is important that you become familiar with the lake or pond that you intend to go out on.
For new, clear ice only
Under 4" - STAY OFF
4" - Ice fishing or other activities on foot
5" - 7" - Snowmobile or ATV
8" - 12" - Car or small pickup
12" - 15" - Medium truck
Many factors other than thickness can cause ice to be unsafe.
White ice or "snow ice" is only about half as strong as new clear ice. Double the above thickness guidelines when traveling on white ice.
- Wear your life jacket. If you fall in, a life jacket will keep you at the surface and can provide insulation against the effects of cold water.
- New ice is stronger than old ice. Four inches of clear, newly formed ice may support one person on foot, while a foot or more of old, partially thawed ice may not.
- Ice doesn't freeze uniformly. Continue to check ice conditions frequently as you venture out onto the ice.
- Ice formed over flowing water and currents is often more dangerous.