Martin Yecies, age 14, Richmond, Virginia for his question:

What is Indian Summer?

We expect the summer to lead into the fall with shorter and cooler days. The weather brings frost and cold spells, and winter is upon us. In the central and eastern part of our continent, however, there is sometimes a change in this neat order of things. After the first cold snap it seems that summer comes back to spend an extra week or so. This late summery spell is known as  Indian Summer.

Some years it does not come at all and some years it may repeat itself two or three times. The days will be warm, maybe quite hot, the night cool. There may be a foggy haze near the ground and a misty smell of smoke and autumn leaves in the air.

Weather experts say that Indian Summer may be caused by a draft of cool air from the polar regions. It moves down to form a shallow pool within a mass of warm air left over from the summer. The result is an anticyclone, a vast mass of lazy air slowly spiraling in towards a central area.