Is There Any Truth in the Old Weather saying of “Red Sky at Night Shepherds Delight” ?
“Red Sky at Night – Shepherd’s delight
Red Sky in the morning – Sailor’s Warning”
This is one of those venerable bits of meteorological lore (and according to Matthew 16, even Christ knew of it) and weather experts confirms it to be around 70% reliable. But Why ?
Well it’s based on the reddish glow of the morning or evening sky, caused by haze or clouds related to storms in the region. If the morning skies are red, it is because clear skies over the horizon to the east permit the sun to light the undersides of moisture-bearing clouds – the saying therefore assumes that more such clouds are coming in from the west. Conversely, in order to see red clouds in the evening, sunlight must have a clear path from the west, so therefore the prevailing westerly wind must be bringing clear skies. Ofcourse this is roughly true on the edge of Western Europe where we are – where we have prevailing south westerly winds.
Because of different prevailing wind patterns around the globe, the traditional rhyme is generally not correct at lower latitudes of both hemispheres, where prevailing winds are from east to west. So the rhyme is generally correct at mid-latitudes where, due to the rotation of the Earth, prevailing winds travel west to east.
Some Other Old Weather Sayings
There is some truth in this saying – if it rains before seven, more than likely it has been raining throughout the night and the storm is drawing to a close. This often gives way to fine weather later in the day.However, as we all know, rain in the UK has a tendency to hang around a lot longer.
The old English proverb is occasionally applied to other situations where it is hoped things will improve after a bad start.
When the night sky is clear, the earth’s surface cools rapidly – there is no cloud cover to keep the heat in.
If the night is clear enough to see the moon and the temperature drops enough, frost will form.
But this saying isn’t true on a clear summer night.
It is believed to be a Scottish proverb but the original source is unknown.