Skip to content
Life Guide U.S. essentials
English

Before stepping onto wild ice, drill a hole and measure the thickness; don't go on if it is under 15 cm, and stay off river ice and the edges of ice-fishing holes

  • Moderate value
  • Evidence C
  • Buys life
  • Costs a little
  • Takes minutes
  • No willpower

In plain words

The official line in China is that ice must be 15 cm thick before adults can skate on it. The U.S. and Canada put the minimum at 10 cm, and that counts only new, clear ice. White ice is only half as strong, so the thickness has to double. On the same sheet of ice it can be a foot thick in one place and only an inch or two a few steps away, so measure as you go.

Cost

The easiest is to go to a properly run ice rink, which costs nothing extra. If you must go on wild ice, bring an ice auger or ice chisel to drill holes and measure the thickness. Also buy a pair of ice picks, two pointed spikes with handles, worn on a cord over the chest. Altogether that is a few dozen to one or two hundred CNY. Measure every so often as you go, which takes extra time.

What you get

The China Meteorological Administration (中国气象局) says in its public-education material that when the ice is 15 cm thick, adults can go on it to skate. Outdoor rinks also need 15 cm of ice before they can open. The Beijing Municipal Water Authority (北京市水务局) says a properly run natural ice rink opens only when the ice is 15 cm thick, and for the following week the temperature stays between -8°C and 1°C with no strong wind. Wild ice often has holes chopped by anglers, and once chopped open they are hard to refreeze solid. The U.S. Minnesota Department of Natural Resources guidance applies only to new, clear ice: stay off if under 4 inches (about 10 cm); 4 inches allows walking and ice fishing. White ice, formed when snow melts and refreezes, is only about half as strong as clear ice, and its thickness should be counted as double. On the same body of water, the ice can be 1 foot thick in one place and only 1 to 2 inches a few feet away. Ice on moving water is usually dangerous, especially near streams, bridges and culverts. Ice near the shore can also be thinner than farther out. The U.S. National Weather Service's thresholds for walking, ice fishing and skating are also 4 inches. The Canadian Centre for Occupational Health and Safety, relaying the Canadian Red Cross's advice, says 15 cm for a group skating or walking, and 20 cm for a crowded skating party. These are all safety guides; no research has calculated how many deaths following them would prevent (national / U.S., Canada).

Notes

The official guidelines all say no ice is 100% safe; reaching the thickness is only a threshold, not a guarantee. Early winter just after freeze-up and early spring when the ice starts to melt are the most dangerous. If you do fall in, don't take your clothes off; the air trapped in thick clothing helps you float. Turn toward the direction you came from, where the ice is strongest. Lay your arms on the ice, dig the ice picks into it, kick your feet behind you and pull your body out. Once out, don't stand up; roll away from the hole lying flat, then warm up as soon as you can, and go to a hospital if you are badly chilled. If you see someone fall through the ice, don't run over to pull them out; for what to do see §13.25 (when you see someone drowning, don't go into the water yourself): call for help and dial 110 first, then pass them a pole or throw a rope. The beneficiary is mainly you and the children you take out on the ice.

Evidence grade
C : The author's experience or common practice, without direct literature.
Sources
  1. 中国气象局 (2019). 想要冰上健步走，多厚的冰才安全？ https://www.cma.gov.cn/kppd/kppdqxyr/kppdtyqx/201901/t20190124_513302.html
  2. 北京市水务局 (2024). 北京正规河湖冰场还未达开放标准，别冒险滑「野冰」. https://swj.beijing.gov.cn/swdt/ztzl/fnsbaqztxc/fnszlxx/202412/t20241226_3973959.html
  3. Minnesota Department of Natural Resources. General ice thickness guidelines. https://www.dnr.state.mn.us/safety/ice/thickness.html
  4. Minnesota Department of Natural Resources. Ice safety. https://www.dnr.state.mn.us/safety/ice/index.html
  5. Minnesota Department of Natural Resources. Steps for surviving immersion. https://www.dnr.state.mn.us/safety/ice/survival.html
  6. National Weather Service. Winter Weather Safety: Ice and Frost. https://www.weather.gov/safety/winter-ice-frost
  7. Canadian Centre for Occupational Health and Safety. Working on or near Ice Covered Water - Basic Information. https://www.ccohs.ca/oshanswers/hsprograms/work_ice.html

Mentioned in

Translated from the Chinese original. Original book, section 1, tip 41. This section is about health and medicines. It is general information, not a substitute for a doctor’s diagnosis or prescription. Content may be out of date and rules differ by place. When you actually deal with an agency, a doctor or a court, follow what local officials, doctors and lawyers tell you. Disclaimer