← Encyclopedia of Astrology · lesson 216/235
Rain stars (anwāʾ)
What it is
Long before Greek astrology reached them, the peoples of Arabia kept time by the stars. Herders and farmers watched the eastern and western horizons in the half-light before dawn. When a star group set in the west just as the Sun was about to rise, its partner on the opposite side of the sky — its raqīb, its "watcher" — was rising in the east. Each such setting was a nawʾ (plural anwāʾ), and every thirteen days or so a new one began.
Weather was tied to these settings: the rain, wind, heat or cold of a stretch of days was said to belong to the star whose nawʾ it was. The star groups used were, for the most part, the same ones the Moon passes through, so when the Arabs met the Indian and Greek idea of lunar stations, they gave the twenty-eight lunar mansions the names of their own rain stars: al-Thurayyā (the Pleiades), al-Dabarān, al-Simāk and the rest.
How it worked
The calendar was solar, not lunar: a star sets at dawn on roughly the same date each year, so the anwāʾ marked the seasons — the first autumn rains, the deep of winter, the coming of summer heat. Some names carry the weather in them. Al-Ṣarfa, "the turning", was explained as the time when the heat turns away; the stars of the four mansions named saʿd, "good fortune", rise at dawn in the late winter and early spring, when the land greens again.
Two cautions. The dates shift with latitude and, over centuries, with precession, so a nawʾ of the Hejaz does not fall on the same day in Andalusia or today. And the scholars who later wrote the "books of the anwāʾ" (kutub al-anwāʾ) disagreed among themselves about which star belonged to which rains.
In Islam
Islam kept the calendar and changed what it meant. A well-known hadith reports God saying of people who had just been given rain: those who say "we were given rain by such-and-such a nawʾ" have put their faith in a star, while those who say "by the grace and mercy of God" are believers. The rain belongs to God; the star only marks the season. Muslim scholars therefore separated knowledge of the stars for timekeeping — the seasons, the direction of prayer, the hours — which was widely accepted and taught, from claims that the stars cause events, which many jurists rejected.
That distinction is a useful one for any reader of astrology. The anwāʾ were never a forecast in the modern sense; they were a way of knowing where one stood in the year.