Editor’s Note: Due to the editor’s vacation, this story’s publication was delayed until now..

By David Muir

On July 6, 2025, there was another spectacular sunset over the Matanzas River that progressed rapidly as the cloudscape transformed the sky within a 10-minute timeframe. This illustrated the amazing dynamics of sunlight, atmosphere, cloud formations and the human eye…and digital camera.

A sunset progresses through a beautiful array of colors due to a combination of light scattering, refraction, and atmospheric conditions. Sunlight is made up of all colors in the visible spectrum—combined, it appears white. As sunlight passes through Earth’s atmosphere, air molecules and particles scatter the shorter wavelengths (blue and violet) more than the longer ones (red and orange). At sunset, the Sun is low on the horizon. This means the sunlight travels a longer path through the atmosphere to reach your eyes.  More of the shorter blue and green wavelengths are scattered out of your line of sight.  What remains are the longer wavelengths—reds, oranges, and pinks—which dominate the sky.

Clouds act like mirrors, catching the Sun’s rays and reflecting colors across the sky, even after the Sun has technically dipped below the horizon. Clouds are made of water droplets or ice crystals, which scatter all wavelengths equally.  But since only red/orange light is reaching the clouds at sunset, that’s the light they reflect down to you. The lower or thicker the clouds, the more vividly they can catch and reflect these warm colors. Early in a sunset, clouds may look white or yellow, as some blue light is still around.  As the sun dips lower, clouds appear orange, pink, red, depending on how much blue/green light has been filtered out.  After the sun sets, only scattered or reflected light remains, leading to purples or grays, before fading to dark.  At any time sunlight that is not reflected by clouds passes to the upper atmosphere and is then reflected by the ozone layer and appears blue. All these dynamics were on full display on July 6 between 8:32 and 8:42.