How Thick Does Ice Need to Be? Ice Safety in Canada
The Canadian Red Cross recommends clear, solid ice at least 15 cm thick for walking, skating or skiing in small groups, 20 cm for larger groups such as skating parties, and 25 cm for snowmobiles or ATVs. Lifesaving Society guidance adds 20–30 cm of clear ice for one car and 30–38 cm for a medium truck. These figures apply only to clear blue ice; white or grey ice is weaker, and no ice is ever completely safe.
How thick does ice need to be?
Two Canadian water-safety organizations publish minimum thickness figures, and they differ slightly. The Canadian Red Cross ice safety tips give the more conservative numbers for people on foot. The Lifesaving Society (Alberta and Northwest Territories) chart covers vehicles as well. When the two differ, we suggest using the thicker figure.
| Activity (clear blue ice only) | Canadian Red Cross minimum | Lifesaving Society guideline |
|---|---|---|
| Any activity | Stay off unless you are sure the ice is thick enough | About 7 cm (3 in) or less: stay off |
| Walking, skating, skiing or ice fishing, alone or in a small group | 15 cm | 10 cm |
| Larger groups, such as skating parties or games | 20 cm | 20–30 cm for a group of people |
| One snowmobile or ATV | 25 cm | 13–18 cm |
| One car or small pickup | No figure given | 20–30 cm |
| One medium truck | No figure given | 30–38 cm |
These are minimums for good-quality ice in ideal conditions, not a promise of safety. Driving on ice adds risks that thickness alone does not capture, so only use official ice roads or areas that local authorities have tested and opened, and follow their posted limits.
What ice colour tells you
The Red Cross notes that the colour of ice indicates its strength and quality: blue ice is the strongest, while grey ice is unsafe. The Lifesaving Society adds that white ice contains air or snow and should be considered suspect.
- Clear blue (or clear green) ice: the strongest. The thickness tables above refer to this ice only.
- White, opaque or "snow" ice: formed when wet snow freezes on top of the ice. It is much weaker than clear ice; treat it with suspicion and do not count it toward your measured thickness.
- Grey ice: a sign of water within the ice. It is unsafe to stand on.
Other warning signs
According to the Red Cross, you should watch for:
- Ice that has frozen, thawed and refrozen; it stays weak until it freezes solid again.
- Snow cover, which insulates the ice and can keep it from freezing fully.
- Pressure ridges, air holes and objects sticking out of the ice.
- Thinner ice near dark objects such as rocks, docks and logs.
- Mist rising from the surface, which can signal open water.
The Lifesaving Society also warns to avoid moving water and water bodies with changing levels, which means rivers, inlets, outlets and areas near dams need extra caution. Spring thaw weakens ice even when it still measures thick enough.
How to check ice thickness
- Check with local authorities first. Many municipalities test and post designated rinks and lakes.
- Go with a partner and tell someone where you are going and when you will be back.
- Wear a lifejacket or PFD; the Lifesaving Society suggests wearing it over your snowmobile suit or winter layers.
- While one person drills a test hole with an auger or chisel, the other stays a safe distance away.
- Measure the clear ice along the inside of the hole with a tape measure or ice gauge.
- Test again every few metres, because thickness varies across the surface.
Avoid going on the ice at night, when open holes are hard to see, and keep children within arm's reach at all times, a point both the Lifesaving Society and Parks Canada make.
Ice picks, rescue gear and self-rescue
Gear to carry
The Lifesaving Society recommends carrying ice picks, an ice staff, a rope and a small personal safety kit. Ice picks are a pair of spiked handles, usually joined by a cord, that you wear around your neck or clip to your jacket so you can reach them instantly. The Red Cross also suggests carrying a pole or long branch to support yourself at the edge and a throwing or reaching device for helping others.
If you fall through: Red Cross steps
- If you can get out immediately, do it. Call for help.
- Resist the urge to climb out where you fell in; that ice is weak.
- Use the air trapped in your clothing to float on your stomach and let your breathing settle.
- Reach forward onto the broken ice without pushing down, then kick your legs to slide your torso onto the ice. Ice picks give you grip here.
- Once out, do not stand up. Crawl or roll away with arms and legs spread to distribute your weight, heading back the way you came.
- If you cannot get out, lift your body as far out of the water as you can and stay still; wet clothing can freeze to the ice and help keep you above water until help arrives.
Helping someone else
The safest rescue is from shore. Call 911, then reach with a pole, rope or branch while lying down. If you must go onto the ice, wear a PFD, stay low, crawl near the hole and extend or throw the device; ask the person to kick while you pull. Then treat them for hypothermia and get medical help.
Ice fishing safety
- Measure as you go and keep drilling test holes as you move to new spots.
- Do not park vehicles or set up shelters in groups unless the ice is rated for the combined load and the area is approved locally.
- If you are ever in a vehicle that breaks through, the Lifesaving Society advises opening the windows, unlocking the doors and unfastening seat belts so you can get out quickly.
- Avoid alcohol; it impairs judgment and speeds the onset of hypothermia.
- Check your provincial fishing regulations and licence rules; see our fishing licence guide.
Ice safety checklist
- Clear blue ice at least 15 cm for people on foot (Red Cross); thicker for groups and machines
- Local authority checked; trip plan left with someone
- Partner, PFD or flotation suit, ice picks around your neck, rope
- Auger or chisel and tape measure; test every few metres
- Stay off grey ice, moving water, pressure ridges and refrozen ice
- No ice outings at night; children within arm's reach
Ice picks, augers and shelters belong in our Fishing & Ice Fishing department, and throw ropes and safety gear in Navigation, Optics & Safety. For skates, see Hockey & Skating. Our catalogue is still being added. This guide is general safety information; always follow local authorities and posted signs.
Frequently asked questions
How thick does ice need to be to walk on?
The Canadian Red Cross recommends at least 15 cm of clear, solid ice for walking, skating or skiing in small groups. The Lifesaving Society lists 10 cm for walking alone; using the thicker figure adds a margin.
How thick should ice be for a snowmobile?
The Red Cross recommends a minimum of 25 cm of clear ice for snowmobiles or ATVs. The Lifesaving Society chart lists 13–18 cm for a single machine.
How thick does ice need to be for a car or truck?
The Lifesaving Society lists 20–30 cm of clear ice for one car or small pickup and 30–38 cm for a medium truck. Only drive on ice that local authorities have tested and opened.
What does the colour of ice mean?
Clear blue ice is the strongest. White or opaque ice contains air or snow and is weaker, and grey ice indicates water in the ice and is unsafe.
What should I do if I fall through the ice?
Call for help, float on your stomach, reach forward onto solid ice, kick to slide out, then crawl or roll away without standing up. Ice picks worn around the neck make getting out easier.