North American Public Avalanche Danger Scale Avalanche danger is determined by the likelihood, size and distribution of avalanches. |
| Danger Level |
Travel Advice |
Likelihood of Avalanches |
Avalanche Size and Distribution |
| 5 Extreme |
 |
Avoid all avalanche terrain. |
Natural and human- triggered avalanches certain. |
Large to very large avalanches in many areas. |
| 4 High |
|
Very dangerous avalanche conditions. Travel in avalanche terrain not recommended. |
Natural avalanches likely; human- triggered avalanches very likely. |
Large avalanches in many areas; or very large avalanches in specific areas. |
| 3 Considerable |
 |
Dangerous avalanche conditions. Careful snowpack evaluation, cautious route-finding and conservative decision-making essential. |
Natural avalanches possible; human- triggered avalanches likely. |
Small avalanches in many areas; or large avalanches in specific areas; or very large avalanches in isolated areas. |
| 2 Moderate |
 |
Heightened avalanche conditions on specific terrain features. Evaluate snow and terrain carefully; identify features of concern. |
Natural avalanches unlikely; human- triggered avalanches possible. |
Small avalanches in specific areas; or large avalanches in isolated areas. |
| 1 Low |
 |
Generally safe avalanche conditions. Watch for unstable snow on isolated terrain features. |
Natural and human- triggered avalanches unlikely. |
Small avalanches in isolated areas or extreme terrain. |
| Safe backcountry travel requires training and experience. You control your own risk by choosing where, when and how you travel. |