When a summer afternoon gets hot and steamy, and great drops of rain splash on the sidewalks and the leaves of trees, everyone knows there's going to be thunder and lightning. But why does it thunder? What makes the lightning?

In this lucid account of a dazzling natural phenomenon, Dr. Branley tells how an electrical charge builds up in a thundercloud until it produces a lightning flash. His wonderfully clear description of the sound barrier explains why we hear thunder after we see the lightning, and how to reckon our distance from the storm.

The author does not ignore the dangers of the storm, but gives simple, reassuring instructions on what to do when one comes. Ed Emberley's lighthearted illustrations provide fun and drama in this easy-to-read book about exciting weather.

From the dust jacket