Ceraunomancy is a form of divination practiced by the ancients consisting of making prognostications by the examination of lightning.

Augurs in ancient Rome practiced Ceraunomancy in the following manner:

• Bolts from the East were considered favorable omens,
• bolts from the West were considered to be inauspicious,
• bolts from the North were the most ominous of all, and
• bolts from the Northwest indicated that extremely bad news would soon be arriving.

In the Middle Ages, some people believed that thunder and lightning in the winter were the portents of war, floods and also of the death of someone important, usually living within a twenty miles radius of the occurrence.

Ceraunoscopy is further branched into Brontoscopy (divination solely by thunder), and Ceraunomancy.