Red sky at morning shepherds warning

Since biblical times and probably before, proverbs and folklore such as this developed as a way for societies to understand and foretell prevailing weather conditions.

The “red sky” proverb has endured across cultures for centuries, and modern science can explain why this is so.

Read more: Here's how a complex low-pressure system sent temperatures plummeting

What causes a red sky at sunrise and sunset?

The Sun is low on the horizon at sunrise and sunset. At these times of the day, sunlight has had to travel through more of the atmosphere to reach us. When light hits the atmosphere it is scattered, particularly when dust, smoke and other particles are in the air.

This scattering affects the blue part of the light spectrum the most. So by the time the sunlight reaches our eyes there is generally more of the red and yellow parts of the spectrum remaining.

Dust and smoke particles commonly build up in the atmosphere beneath high-pressure systems, which are generally associated with dry and settled weather.

If you’ve ever been to Darwin in the Northern Territory during the dry season (the period between May and September), you’ll know glorious red and orange sunsets are an almost daily occurrence.

This makes sense – the sky across the Top End at this time of year is often full of dust particles whipped up off the land by dry southeasterly winds, as well as smoke from bushfires burning through the landscape.

What can red sky tell us about the weather?

In areas of the world where weather systems move routinely from the west to the east, including across southern areas of Australia, the “red sky” proverb often holds true.

A red sky sunrise suggests that an area of high pressure and fine weather, with its trapped dust and other particles, has moved out towards to the east. This allows for an area of lower pressure and deteriorating weather – perhaps a cold front and band of rain – to move in from the west during the day.

On the other hand, a red sky sunset tells us the worst of the weather has now eased, with higher pressure and improving weather approaching from the west for the following day.

Across northern Australia and other areas of the tropics, the “red sky” proverb is an unreliable method to predict the weather. In these regions, weather patterns are often very localised, moving in no particular direction at all, and larger tropical weather systems usually move from east to west.

Red skies and cloud

What often makes red sky sunrises and sunsets even more spectacular is the position of the Sun in the sky, relative to cloud.

When the Sun is low on the horizon, rays of light shine back up onto the underside of cloud high in the sky, reflecting back those bright orange and red colours that make it look as if the sky has turned to fire.

With a red sky sunrise, the eastern sky is more likely to be cloud-free with finer weather, allowing the Sun to shine upon the higher cloud moving in with the deteriorating weather from the west.

With a red sky sunset, it’s the western sky more likely to be clear, with the Sun’s rays shining up onto cloud further east.

So the next time you spot a spectacular sunrise or sunset, keep the “red sky” proverb in mind and you’ll become a pro at forecasting the weather in no time!

Many of us will have heard the old adage about red skies at night in the form of the ‘shepherd’s warning’ rhyme.

If you haven't heard it before, it goes something like this– ‘Red sky at night – shepherd’s’ delight/ Red sky in the morning – shepherd’s warning.’

Go here for the very latest breaking news updates from across the North East

But what does a red sky really mean? Why does it happen? And does it actually impact the weather?

If you’ve ever asked any of these questions, then here are all the answers you’re looking for thanks to the Mirror.

Why does the sky turn red in the morning?

Periods of high pressure during winter can lead to cold, dry days, with light winds.

These winds cause dust and other particles to become trapped within the atmosphere.

This means that when the sunlight moves through the sky, the red wavelengths pass through the air more easily than blue ones tend to deflect and get scattered, leaving the sky tinged red.

Sometimes, when the red light is reflected on white clouds it gives the appearance of pink clouds as well.

What does the ‘shepherd’s warning’ rhyme have to do with the red sky?

For over 2000 years, shepherd’s (or sailor’s) rhyme – which also appears in the Bible - has been used as a rule of thumb for predicting the weather.

The 'shepherd’s warning' means that the weather following a day with a red sky was going to be poor – something which shepherds and sailors both had reason to be wary of.

Is the ‘shepherd’s warning’ rhyme true?

Despite the science behind the red sky, the ‘shepherd’s warning’ rhyme does hold some truth to it as well, as long as you’re somewhere along the middle latitudes of the planet.

In the UK, weather systems move predominantly from west to east.

A red sky in the morning therefore means that the sky is clear to the east, where the sun is rising, but cloudy overhead.

This suggests that the clouds are beginning to move in bringing in bad weather with it.

Meanwhile, a red sky at sunset means high pressure is moving in from the west and therefore the next day will usually be dry and pleasant.

However, in the tropics, where the winds blow in the opposite direction, the saying about red skies doesn’t work.

For the latest local news in your area direct to your inbox every day, go here to sign up to our free newsletter

What does red sky in morning sailors take warning mean?

What is the full saying red sky at night shepherd's delight?

What does a red sky mean biblically?

Where does Red Sky in the Morning sailors Take Warning come from?