Red Sky at night... weather proverb explained

“Red sky at night, sailor’s delight; red sky in morning, sailor’s warning.”

While this weather proverb (and its many variants) is probably the most well known in our culture, its truth is a little more complicated than is typically understood. This is because the proverb isn’t actually specific enough for us to accurately predict the weather.

A red sky at night can indeed mean fair weather, but particularly if the red appears in the eastern sky. A red night sky in the east likely means that the light of the setting sun is passing through the low atmosphere and reflecting off clouds. If this is the case, it’s possible that rain has already passed, and you’re in the clear.

A red western sky at night can mean a couple things, depending on the shade of red. A more pinkish hue can portend clear, fair weather, but a deep red sky at night to the west can mean that moisture is collecting in the air, and a storm system is forming.

The “red sky in morning” half of the proverb can be equally vexing.

Beyond just the atmospheric explanations, pollution and other unnatural particles in the air can drastically affect the color of the sky in all directions and all times of day.

So while you’ll find quick answers and explanations to the proverb online in other web sites, a red sky can ultimately mean different things based on a variety of factors, both natural and not-so-natural. While it’s a quippy proverb, the other explanations you’ll find online will better help you predict the weather in the coming days.