Wanda Levis., Age 12, Of Mt. Holly, N.C., For her question:

Does it ever get too cold to snow?

Snowflakes form from water vapor in the air, and as a rule there is more vapor in warm air than there is in cold air. Havever, there is always a certain amount of vapor, even in the coldest, driest air. So even in the coldest weather, there are some molecules of vapor which can be frozen and assembled into snowflakes.

In theory, then, it can never get too cold to snow. But in very cold weather, there is little moisture in the air, so if snow forms, it will be light. In Alaska, snow has been known to fall when the temperature dipped to a chilly 52 degrees below zero.