Predicting Weather By The Moon - Xavier University Libraries

Early Moon Watchers
lore was Aristotle’s pupil Theophrastus. His Book of Signs,
written about 300BC, described more than 200 portents
of rain, wind and fair weather, and a few that were alleged
to reveal what the weather would be like for the coming
year or more. As well as introducing cloud folklore(‘in the
morning mountains, in the evening fountains’) he described
signs to be found in the behaviour of sheep, the way a lamp
burns during a storm (probably due to atmospheric changes)
and the crawling of centipedes toward a wall.
He was the first to note that a halo around the Moon
signified rain coming. He also claimed that flies bite excessively
before a storm. Research shows this to be incorrect,
unless they had different flies 2000 years ago. Nevertheless,
his book was a major reference work for forecasting
for the next 2000 years. The Roman poet Virgil(70-
19BC), in his agricultural treatise The Georgics, said
‘The father himself laid down what the Moon’s phases should
mean, the cue for the south winds dropping..’
He also wrote
‘Nor will you be taken in by the trick of a cloudless night
When first at the New Moon her radiance is returning
If she should clasp a dark mist within her unclear crescent
Heavy rain is in store for farmer and fisherman’
The earliest known almanac was written in Egypt in
about 3000BC. Almanac is an Arabic word that means ‘Calendar
of the skies.’ When Columbus sailed west 500 years
ago, around an Earth he thought was shaped like a modern
rugby ball, he, like other sailing captains of his time, had in
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