Can we see a green or purple sky at sunrise or sunset?
General knowledgeAsked by Anonymous from Mountain View, United States1 Oct 2026, 8:07 AM ISTUpdated
In one line
Yes, sometimes you can see a green or purple sky at sunrise or sunset, but it is rare.
Sunset — Daily falling of the Sun below the horizon A sunset showing orange, red, and sometimes purple hues due to light scattering. Image: Wikipedia
The rule
The colour of the sky at sunrise or sunset depends on how sunlight is scattered by the atmosphere.
Let's understand it simply
Imagine you are playing cricket in the evening. The sun is low, and the sky looks orange or red. This happens because sunlight has to travel through more air. The air scatters (spreads out) the blue and green light, so mostly red and orange reach your eyes.
But sometimes, special conditions can make the sky look green or purple. It is like when you mix different colours in a painting—sometimes, you get a new colour by accident!
How it works
Sunlight is made of many colours: red, orange, yellow, green, blue, indigo, violet.
When the sun is low, its light passes through more air.
The air scatters blue and green light away from your eyes.
If there are clouds, dust, or pollution, they can scatter light differently.
Sometimes, enough red and blue mix together, making the sky look purple.
Rarely, green can appear if certain conditions are just right, like after a storm or with special clouds.
How sunlight creates sky colours at sunset
Sunlight enters the atmosphere at a low angle.
Blue and green light scatter away.
Red and orange light reach your eyes.
Sometimes, mixing of red and blue makes purple.
Rarely, special conditions create green flashes.
The story behind it
Scientists like Lord Rayleigh studied why the sky is blue and sunsets are red. He found that small particles in the air scatter blue light more than red. This is called Rayleigh scattering. Later, other scientists explained how mixing colours can sometimes make the sky look purple or green.
Where you see it in real life
Sunset after rain: Sometimes, after a heavy monsoon shower, the sky can look purple because of extra water droplets scattering light.
Green flash: Rarely, just as the sun sets, you might see a quick green spot—this is called the 'green flash.'
Dust storms: In Rajasthan, after a dust storm, the sky can look strange colours, sometimes greenish or purple, due to dust scattering light.
Pollution: In big cities like Delhi, pollution can make sunsets look more colourful, sometimes with purple or greenish hues.
Why it matters
Helps us understand how light and the atmosphere work.
Shows how pollution or weather can change what we see.
Useful for artists and photographers who want to capture these rare colours.
Important for weather scientists to study unusual sky colours.
Common mistakes
Thinking the sky is always blue, orange, or red—other colours are possible but rare.
Believing green or purple skies are always a sign of danger—they can be natural.
Mixing up the 'green flash' with a long-lasting green sky—the flash is very quick.
Remember it
At sunrise or sunset, the sky can show many colours—sometimes even green or purple, if the conditions are just right.
Check yourself
Why does the sky usually look red or orange at sunset?
Because blue and green light are scattered away, leaving red and orange to reach our eyes.
What is the 'green flash'?
A quick green spot seen just as the sun sets or rises, caused by atmospheric conditions.
Can pollution affect the colour of the sky at sunset? How?
Yes, pollution can scatter light differently, making sunsets look more colourful, sometimes purple or greenish.
Quick recap
The sky can sometimes look green or purple at sunrise or sunset.
This happens due to the way sunlight is scattered by the atmosphere.
Dust, pollution, or clouds can help create these rare colours.
The 'green flash' is a real but rare event at sunset or sunrise.
