The weather has taken some dramatic swings in New Hampshire this winter, from rain to snow and below zero temperatures to springlike 60s, not to mention the wind. All of this change can affect the thickness and quality of the ice on rivers, ponds, and lakes. New Hampshire Fish and Game Department officials urge outdoor enthusiasts to exercise caution when enjoying winter and spring activities on the ice.

“It is imperative that you personally check the ice thickness on a waterbody as you venture out on foot, or before riding out on a snowmobile or off-highway recreational vehicle,” said Captain Dave Walsh, who coordinates OHRV Enforcement and Safety Education for Fish and Game.

“Do not assume that because the ice is safe in one location that it will also be safe 100 yards away. If you don’t know, don’t go,” he warned.

Because ice conditions can be unpredictable and lack uniformity, it is not advisable to drive vehicles onto the ice. People walking on ice should carefully assess its safety before venturing out by using an ice chisel, ax, or auger to determine the thickness and condition. Continue to check the ice as you get further out onto it; don’t just check along the shore.

A short video demonstrating how to check ice thickness can be viewed at

Walsh adds that you should also be sure to always bring along a rescue rope, ice picks, and a personal flotation device such as a float coat or conventional life jacket.

Though all ice is potentially dangerous, the U.S. Army Cold Regions Research and Engineering Laboratory in Hanover offers a rule of thumb on ice thickness: There should be a minimum of six inches of hard ice before individual foot travel, and eight to 10 inches of hard ice for snow machine or OHRV travel. Weak ice is formed when warming trends break down ice, then the slushy surface re-freezes. Be especially careful of areas with active currents, such as inlets, outlets, and spring holes where the ice can be dangerously thin.

Tips for staying safe on the ice include:

  • Stay off the ice along the shoreline if it is cracked or squishy. Don’t go on the ice during thaws.
  • Watch out for thin, clear, or honeycombed ice. Dark snow and ice may also indicate weak spots.
  • Small bodies of water tend to freeze thicker. Rivers and lakes are more prone to wind, currents and wave action that weaken ice. Ice can be thinner near structures such as docks or fallen trees.
  • Don’t gather in large groups or drive large vehicles onto the ice.

If you do break through the ice, don’t panic. Move or swim back to where you fell in, where you know the ice was solid. Lay both arms on the unbroken ice and kick hard. This will help lift your body onto the ice. A set of ice picks can help you pull yourself out if you do fall through the ice; wear them around your neck or put them in an easily accessible pocket. Once out of the water, roll away from the hole until you reach solid ice.

Ice safety is also very important for snowmobilers. Don’t assume a trail is safe just because it exists; ask about trail conditions at local snowmobile clubs or sporting goods shops before you go.

“We want everyone to enjoy all that New Hampshire has to offer, but safely,” continued Walsh. “Children especially need to be taught not to go on the ice unless an adult has checked and told them it is safe.”

Visit the New Hampshire Fish and Game website at for more information.