“A red sky at night is a shepherd’s delight! A red sky in the morning is a shepherd’s warning.”

Perhaps this saying came to mind if you caught a spectacular sunrise or sunset recently.

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.

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.

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.

read more at sciencealert.com