In the evening, the western sky turns a soft pink, and someone is bound to say: "It'll be a lovely day tomorrow." Others are sure that a red sunset means wind. We look at who's right, and why this particular piece of weather lore, unlike so many others, has a scientific basis.
Sayings about sunsets exist in almost every culture. In England, people say: "Red sky at night, shepherd's delight; red sky in the morning, shepherd's warning." In Russian villages, people noticed that a sun setting "into a cloud" promised bad weather, while a red sunset meant wind.
In January 2023, when a vivid crimson sunset spread over Yekaterinburg, residents bombarded forecasters with questions about what it meant. Let's work out when you can trust a pink sky and when you can't.
Where the Pink Comes From
As the sun sinks towards the horizon, its light has to travel a long way through the atmosphere. Along the way, air particles scatter the blue and green rays, and what reaches us is mostly orange, red and pink.
"As a result, only the long-wavelength part of sunlight remains visible," explains meteorologist Alexei Pulin.
How vivid the sunset is depends on what's in the air. Fine dust particles and dry aerosols increase the scattering.
"Dry air is exactly what contains the dust that scatters the sun's rays," says Pulin.
Thick cloud and damp haze, on the other hand, dull the colours, leaving the sunset grey or washed out.
Why a Pink Sunset Means Good Weather
In the mid-latitudes, where most of Russia lies, weather usually moves from west to east. So when we look at the sunset in the evening, we're looking in the direction tomorrow's weather will come from.
If the western sky is clear and sunlight can turn it pink unhindered, dry, settled air is on the way rather than rain clouds. The UK's Met Office explains it like this: a red evening sky indicates that an area of high pressure is approaching from the west, so the next day is likely to be dry and clear.
Andrei Khoroshilov, founder of the environmental service Sokhrani Les ("Save the Forest"), agrees: if "the western horizon is relatively clear" in the evening, the good weather is likely to hold. This piece of lore fits well with modern understanding of how weather fronts move.
And if the Sky Is Red in the Morning?
The morning version of the saying works the other way round. At dawn, we look east, which is where the good weather has already gone.
If the east is red and clouds are gathering in the west, the anticyclone has already passed, and an area of low pressure, bringing wind and rain, may be approaching from the west.
That's exactly why the English saying calls a red morning sky a "warning".
When the Saying Gets It Wrong
The sunset saying is one of the best founded, but it isn't infallible.
- Weather Doesn't Always Come From the West
Weather fronts in the mid-latitudes sometimes arrive from the south or the north, and in summer thunderstorms often form on the spot after the ground has heated up during the day. The Met Office says plainly that the saying "often" holds true, but not always.
- A Crimson Sunset Can Mean Wind
A vivid deep-red colour points to a large number of particles in the air. According to Alexei Pulin, a sunset like this can signal strengthening winds at altitude, which then reach the ground too. So the folk saying "a red sunset means wind" also has some truth in it.
- Smoke and Dust Change the Picture
During wildfires or dust storms, sunsets become especially bright and red, but this has nothing to do with the weather: it's caused by smoke particles in the air.
- Forecasters Know Better
In January 2023, when Yekaterinburg residents linked the crimson sunset to bad weather, Galina Sheporenko, chief forecaster for the Sverdlovsk region, urged people not to rely on folk signs. In fact, the forecast promised milder weather and no significant precipitation.
How to Read a Sunset Properly
Look west, not just at the colour. What matters is whether the horizon is clear in the direction the weather will come from. A pink sunset with a cloudless western sky is a good sign, while a sun setting into a thick bank of cloud points to a possible change for the worse.
A soft pink sky signals clean, dry air and, as a rule, clear weather. A deep red or crimson sunset more often points to dust, haze or strengthening winds.
Compare it with the morning. If there was a pink sunset in the evening and the sky is clear again in the morning, the day is likely to be fine. If the east is red in the morning and there are clouds in the west, take an umbrella.
Check the forecast. A sunset is a good guide for the next 24 hours, especially out in the countryside where there's no phone signal. But for plans several days ahead, a forecaster's prediction is more reliable.
