Sun dogs, also known as parhelia, are bright spots that appear on either side of the sun, creating a stunning halo effect. They form when sunlight interacts with ice crystals in the atmosphere, typically in cold weather.
These atmospheric phenomena occur when:
- Temperatures are cold enough for ice crystals to form in the air
- Hexagonal plate-shaped ice crystals are present
- Crystals are oriented horizontally as they fall
The ice crystals act like prisms, refracting sunlight at a 22-degree angle, creating bright spots that often display rainbow-like colors. Sun dogs are most commonly seen during winter months but can occur anywhere if conditions are right.