Red sky at night,
Red sky in the morning,
Before the days of people in garish outfits predicting the weather at the end of the news, the person to ask for an update was a farmer. Farmers, more than many other professions, rely on knowing what the atmosphere has in store to aid them in their work, and meteorolgy was an entirely different (though, I’d wager, no less imprecise, science). There was in the past, as there is now a number of contraptions available (barometers, for example, were invented in the 1600s), but reading the sky itself also played an important part. Folk-knowledge has often been passed around through rhyme, and Red Sky at Night is just one example of this tradition.
The rhyme has equivalents throughout the world. In the USA the rhyme replaces shepherd’s sailors; in France, the rhyme runs;
Rouge le soir, bel espoir,
Rouge le matin, de la pluie en chemin.
Rosso di sera, bel tempo si spera,
Rosso di mattina mal tempo si avvicina.
Which both translate (roughly) as, Red in the evening, hopfully fine/ Red in the morning, rain on the way.
A similar sentiment is expressed in the Bible:
2 – He answered and said unto them, When it is evening, ye say, It will be fair weather: for the sky is red.
3- And in the morning, It will be foul weather to day: for the sky is red and lowering. O ye hypocrites, ye can discern the face of the sky; but can ye not discern the signs of the times?
Matthew 16: 2-3 (King James Version)
Is there any truth to this particular bit of folklore? According the website Everyday Mysteries, there is:
Red sky at night, sailors delight.
When we see a red sky at night, this means that the setting sun is sending its light through a high concentration of dust particles. This usually indicates high pressure and stable air coming in from the west. Basically good weather will follow.
Red sky in morning, sailor’s warning.
A red sunrise reflects the dust particles of a system that has just passed from the west. This indicates that a storm system may be moving to the east. If the morning sky is a deep fiery red, it means a high water content in the atmosphere. So, rain is on its way.
So, now you know.