The vibrant colors of sunrise and sunset are caused by a process called atmospheric scattering. During these times, sunlight travels through more atmosphere to reach our eyes because of the Sun’s low angle. This results in:
- Most blue light being scattered away from our line of sight
- Red and orange wavelengths passing through more directly
- Particles and pollution enhancing the effect
The phenomenon is called golden hour or magic hour by photographers. The colors appear most intense when there are some clouds to reflect and scatter the light, and when the air contains dust or water vapor particles.