When the sun is low on the horizon, it can give the sky an orange cast. This effect has nothing to do with pollution and is a normal part of how our eyes perceive color.

As the sun rises in the east and sets in the west, its light must pass through more of Earth’s atmosphere to reach our eyes. Our atmosphere contains molecules that scatter blue light more than red light, which means that as sunlight passes through our atmosphere, some of its blue light gets scattered away. The remaining red light hits your eye as orange.

The farther away you are from a source of illumination (such as an overhead lamp), the more likely you are to notice this effect because there will be fewer particles between you and the source of illumination for light to pass through before reaching your eye.

You may have noticed this effect when looking at streetlights or traffic lights at night — they appear redder when viewed from farther away due to their lower intensity compared with daylight conditions.

Last modified: August 2, 2022