Winter is usually the time for outdoor activities like ice-skating or cross-country skiing. This year, however, the unseasonably mild conditions have limited the opportunities for many traditional winter sports across the U.S.

A brief cold blast of winter, like the one forecast for the New York City area this weekend, is generally not enough to form ice capable of supporting significant weight.   Below is a guideline on how thick ice needs to be to support different activities. The measurements refer only to new, clear, solid ice.  White ice usually has air trapped inside it and is consequently not very strong.

The thickness of ice can vary dramatically from spot to spot on the same pond or lake. Therefore, it is always best to follow the instructions of local officials and posted signs.  When in doubt, stay off the ice.  It is better to be safe than sorry.

Chart Source: Minnesota Department of Natural Resources