Deth

Even when I was a small child, and we had the occasional tropical storm approaching, I remember the sky being so vivid. Sunrises and especially sunsets were always so colorful. I had deducted that it was due to the storm, but never did know why then

Of course now I do.

When the sun is setting or rising, it must pass through more of the atmosphere. That scatters and attenuates some of the blue and violet light since it has to pass through more of the atmosphere with the gases that in it scattering them more. It’s the same reason why the sky is blue during the day. Since the blue light is the most scattered it makes the entire sky look blue.

This leaves the reds and oranges as the dominant light wavelengths to be reflected from the clouds. They cloud tend to be high clouds before storms and well above the dust and stuff in the lower atmosphere, which block more of that light. If the clouds are too low, the bigger partials of dust and stuff blocks too much or the longer wavelengths of the sunlight, so you don’t really get the color.