Aeromancy (from Greek ἀήρ aḗr, "air", and manteia, "divination") is divination conducted by interpreting atmospheric conditions. Alternate spellings include arologie, aeriology and aërology.
Aeromancy uses cloud formations, wind currents and cosmological events such as comets to attempt to divine the future. There are sub-types of this practice which are as follows: austromancy (wind divination), ceraunoscopy (observing thunder and lightning), chaomancy (aerial vision), meteormancy (meteors and shooting stars), and nephomancy (cloud divination).
The first recorded instance of the word aeromancy being used was found in Chambers, Cycl. Supp, 1753. It was defined as "That department of science which treats of the atmosphere", rather than a form of divination. However, variations on the word have been used throughout history with the earliest instance being in the Bible, though the practice is thought to have been used by the ancient Babylonian priests.
Aeromancy was mentioned in Deuteronomy 18 as being condemned by Moses. It is also condemned by Albertus Magnus in Speculum Astronomiae, who describes the practice as a derivative of necromancy. The practice was debunked by Luis de Valladolid in his 1889 work Historia de vita et doctrina Alberti Magni.
In Renaissance magic, aeromancy was classified as one of the seven "forbidden arts," along with necromancy, geomancy, hydromancy, pyromancy, chiromancy (palmistry), and spatulamancy (scapulimancy).