Why Are Some Clouds Pink?

The color of clouds entirely depends on the color of light being transmitted to them from the sun, which is the earth’s natural source of light. The sun provides white light, which, when combined with all the colors in the visible spectrum, we get electromagnetic waves of differing lengths.

When most people think of or draw clouds, it is usually the white puffy clouds that come to mind. However, clouds come in a variety of colors.

The cloud is composed of tiny water and or ice droplets, and the color of the water is colorless. However, we see clouds in different shades and colors, and the color of clouds varies depending on the cloud’s thickness, which can be explained through a phenomenon called scattering.

When light is permitted through the clouds, the water or ice droplets begin to scatter the light, and if the cloud is thin, light passes quickly, allowing us to see a white color.

With the increase of the cloud’s thickness, the number of scattering events is also increased, which results in the color changing of the clouds. The increasing thickness changes the color to grey, and if the cloud is very thick, we see a black shade color.

The color of clouds depends on their density, their makeup of ice crystals, and water vapor. In high-level clouds with frigid temperatures, the ice crystals often reflect bright, white light. This is experienced even at the top of dark and cumulonimbus storm cells due to the thermal updraft energy possessed by these cells.

Quick Navigation

What Are the Different Cloud Colorations?

Clouds don’t have a specific color, as they are made of water vapor or ice droplets. When illuminated by colored light, however, such as the sunrise or sunset. Clouds appear darker as they get thicker to minimize the amount of light transmitted. When light travels to the atmosphere, it affects how colors are scattered and the clouds’ color. 

When using the visible electromagnetic spectrum, blue scatters more than the other colors as it is the shortest wavelength, which is why the sky is mostly blue. When light rays hit droplets of water in the clouds, light is equally scattered, and the combined colors make the clouds appear white.

When the clouds are thicker, they tend to appear more grey than blue or white. When there is a significant presence of water molecules within the clouds, the clouds appear grey. At times during sunrises and sunsets, the sun is located at a lower angle forcing the light to travel through more atmosphere.

When this happens, it allows for more colors to be scattered, revealing the oranges and reds. These colors are then reflected onto the clouds to form pinkish clouds.

Why Are There Pink Clouds?

Some people argue that the color of clouds depends primarily on the cloud’s thickness. This is explained as when sunlight is transmitted through a cloud, tiny droplets of water cause the cloud to scatter all light colors in the same way.

This produces a white color, and as the cloud thickens, less light is allowed through the cloud’s base, so it appears darker.

Clouds themselves are colorless, as stated, mostly because they are composed of ice and water droplets, but there is a catch to it. These water and ice droplets can reflect and absorb light, which is why they appear white when light is reflected from them. Clouds tend to take a darker color when more light is absorbed or blocked from meeting the naked eye.

When you are looking at a cloud, your location can also affect the cloud’s color in your eyes. For example, if you are standing under the base of a very tall cloud, the cloud appears grey as little light is permitted through the cloud, but if you stand further away and view the cloud from the side, it appears white because light doesn’t pass through the cloud before reaching your eye.

Light from the sky is caused by the Rayleigh scattering of sunlight, which leads to the blue sky color perceived by most human eyes. When it is sunny outside, the Rayleigh scattering causes the blue gradient.

The blue color is seen at the horizons because the blue light emanating from a distance is preferentially scattered. When this happens, a redshift of the sources of light is a bit distant, and this is compensated by a blue hue or red light scattering.

At distances and near infinitude, the scattered light appears as white, and the distant clouds and snowy mountaintops seem yellow, and the effect is only pronounced on cloudy days when the blue hue is reduced from scattered sunlight.

The sky can turn to various colors, including orange, red, yellow, and pink. This is mostly experienced near sunrises and sunsets and black at night. This scattering effect of sun rays partially polarizes the light from the sky, and it is most effective at 90 degrees angle from the sun.

Cloud coloration

As observed from the earth, the clouds’ color tells a lot about what is happening inside the particular cloud. Cloud droplets scatter light efficiently, which decreases the intensity of solar radiation with depth into gases.

When this happens, the cloud base varies from a light to a very dark grey color depending on the cloud’s thickness and the amount of light being reflected and transmitted back to you.

Thin clouds look or appear to have an acquired color of their background or their environment. The non-tropospheric and the high tropospheric clouds appear mostly as white, and as a tropospheric cloud matures, dense water droplets can combine to form larger droplets. This accumulation process allows more light to penetrate the clouds, which is what causes a range of cloud color.

Red, pink, and orange clouds are usually seen during sunrises and sunsets, and they are an impact of the atmosphere’s scattering of sunlight. When the angle between the horizon and the sun is small or less than 10%, especially if it’s just after or before sunset, the sunlight appears too red due to the refraction of colors other than red.

The scattering of light in a way that makes red and blue wavelengths predominantly combine to meet the eye produces a perception of pink color in the clouds. There is speculation that clouds appear as pink when they are sitting between our eyes and the horizon so that they predominantly reflect blue wavelengths to our eyes.

When this blue wavelength combines with the predominantly red wavelength reaching your eye from the setting sun’s light, clouds appear pink. The perception of white clouds reduces the effect of the green wavelength, so instead, we have pink clouds.

Why Do Clouds Appear Pink At Sunsets?

When the sun sets, light has no further way to travel, and the sun is usually lower down in the clouds. Light is composed of different colors, hence rainbows, and out of all those colors, blue travels the farthest and scatters out before reaching our eyes. On the other hand, red light can reach our eyes, which is why the sky appears as pink and red more than usual.

Some people argue that these clouds aren’t pink and appear that way at certain times of the day only. This is as a result of the amount of atmosphere passed through by the sunlight. Blue and violet colors are easy to scatter where people can see them, and if the light has a high angle, only these colors are scattered, hence why the sky is usually blue.

This angle is altered during sunsets and sunrises, and as the sun angle is low, light must pass through a lot more of the atmosphere. The violet, yellow, and blue colors are completely scattered out of your sightline, which leaves you with the red and orange colors to see. Hence the clouds appear pink around sunrise and sunset.

The time of day also impacts the color of clouds and causes clouds to appear pink. When the sky appears pink, the clouds reflect the color pink, which is influenced by the time of the day and the sun’s angle. 

The light from the sun contains all the rainbow colors, and even if the color of pure sunlight is white to our naked eyes, it is usually filled with color. Light traveling through the sky passes through evaporated gas and water, clouds, and other atmospheric particles. These particles reflect and refract light, which scatters some of the colors of the sunlight. 

The longer the distance covered by sunlight through the sky, the more colors are lost by the sunlight. Some colors make it, and during sunrise, the sunlight has longer distances to cover across the sky before it reaches your eyes. The colors that reach your eyeballs are pink, orange, and red, less likely to be scattered through the atmosphere. This is what causes the morning sun to fill the sky with a blaze of reds and pinks.

Why Does the Sky Have a Pink Hue When It’s Snowing?

The color of the sky and the clouds is greatly affected by the reflection of light from the sun through the horizon to our eyes. When measuring wavelengths, it’s evident that the red light has a longer wavelength, restricting it from scattering as easily as greens and blues colors. This causes sunsets to appear as typically orange or red, giving the sky a pink hue.

When the sky is moving in, or when it’s already snowing, the light that bounces off the atmospheric particles and the clouds is scattered, which leaves us to see longer wavelengths. When it begins to snow, the same light reflects off all the various snowflakes, which gives the sky a pink hue, hence pink clouds.

There may also be different hues and tint in the sky and the clouds as a result of artificial lighting in the cities/. The color of the clouds varies depending on the color of lighting, which is what causes you to see yellows, pinks, and whites. Low clouds cause snowflakes to drop, and when you have a reasonable speed rate of falling snow, light is reflected off the snowflakes.

Pink Clouds and Sailing

The idea of a red sky at night, sailor’s delight, is derived from the same idea of light reflection. This simply means that if you see a red glow in the night sky, there is a high chance that a storm is either passing through or already has passed. The setting sun’s light in the west reflects off the cloud’s backside, which results in drier and better weather the following day.

When the clouds are in the right position and expansive enough, you can often notice pink clouds during sunrises and sunsets. The clouds appear as a wall of glowing magenta light of pink hue.

The sky usually looks blue due to the small oxygen molecules that interrupt and scatter the blue wavelengths. Some people believe that the high-level cloud invisibility to the eye reflects the blue wavelengths to our eyes.

This combines with the sun’s incoming red wavelengths, which transit through the lower thick atmospheric levels, resulting in a pink perception in the clouds.