Recommended Minimum Ice Thickness for New Clear Hard Ice No ice is without some risk. Be sure to measure clear hard ice in several places. 4 " Less than 4 " STAY OFF! Cross Country Skiing Ice Fishing Walking One VehicleSnowmobile or ATV 5 " 8 -12 " " One VehicleCar or Small Pick-up 12 -15 " " One VehicleMedium Truck 2222