“Red sky at night, sailor’s delight. Red sky in morning, sailor’s warning” true, or is it just an old wives’ tale?

Last night we experienced gale force winds up to 73kmh, and this morning the clouds unleashed sleet, hail and heavy rain – so was yesterday’s glorious red sunrise a warning of  things to come?

Have you ever heard anyone use the proverb above? Shakespeare did. He said something similar in his play, Venus and Adonis. “Like a red morn that ever yet betokened, Wreck to the seaman, tempest to the field, Sorrow to the shepherds, woe unto the birds, Gusts and foul flaws to herdmen and to herds.”

In the Bible, (Matthew XVI: 2-3,) Jesus said, “When in evening, ye say, it will be fair weather: For the sky is red. And in the morning, it will be foul weather today; for the sky is red and lowering.”

Weather lore has been around since people needed to predict the weather and plan their activities. Sailors and farmers relied on it to navigate ships and plant crops.

But can weather lore truly predict the weather or seasons?

Weather lore concerning the appearance of the sky, the conditions of the atmosphere, the type or movement of the clouds, and the direction of the winds may have a scientific basis and likely can predict the weather.

In order to understand why “Red sky at night, sailor’s delight. Red sky in morning, sailor’s warning” can predict the weather, we must understand more about weather and the colours in the sky.

Usually, weather moves from west to east. In the mid-latitudes, the prevailing winds are westerlies. This means storm systems generally move in from the West.

The colours we see in the sky are due to the rays of sunlight being split into colours of the spectrum as they pass through the atmosphere and ricochet off the water vapor and particles in the atmosphere. The amounts of water vapor and dust particles in the atmosphere are good indicators of weather conditions. They also determine which colors we will see in the sky.

During sunrise and sunset the sun is low in the sky, and it transmits light through the thickest part of the atmosphere. A red sky suggests an atmosphere loaded with dust and moisture particles. We see the red, because red wavelengths (the longest in the colour spectrum) are breaking through the atmosphere. The shorter wavelengths, such as blue, are scattered and broken up.

Sunset Brenton on Sea – Pic by Mark Beard

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.

Sunrise over lagoon ~ Pic by  Ivor Abelheim

Red sky in morning, sailor’s warning.

A red sunrise can mean that a high pressure system (good weather) has already passed, thus indicating that a storm system (low pressure) may be moving to the east. A morning sky that is a deep, fiery red can indicate that there is high water content in the atmosphere. So, rain could be on its way.