Great Land of Alaska

Safe Loads for Clear Ice

The thicknesses here are a rough guide. The actual thickness needed to perform these activities may vary depending upon ice clarity. Opaque ice is not as strong as clear ice so the thickness required for activities on opaque ice is greater than that require for clear ice.

Be aware that just because the ice may be thick enough for an activity in one area, it may not be the same thickness in another. Warm springs, currents, vegetation, and other factors may cause ice on lakes to vary greatly in thickness. River ice is very unpredictable as changing currents may weaken ice that was previously thick enough to safely walk on.

The thicknesses given here are not based upon my own personal experience, rather they were obtained from another source. My own personal recommendations is to not venture onto the ice by foot until it is at least 1 foot (30cm) thick, and not drive on it until it is at least 2 feet (61 cm) thick.

Thickness of Ice	Load or Activity
3 inches 8 cm	Cross country skiing
4 inches 10 cm	1 person ice fishing
5 inches 13 cm	1 snowmachine
6 inches 15 cm	1 ice boat
7 inches 18 cm	Group activities
8 inches 20 cm	1 car or truck
9 inches 23 cm	Several vehicles