Sundogs, 22 degree parhelia, mock suns - all names for one of the most common halo effects. Sundogs are formed by light passing through the sides of hexagonal plate shaped crystals, falling with their bases horizontal. Each ice crystal acts as a small prism so the brightest and most colourful sundogs occur when a large proportion of crystals are free of defects. The most common halo effect in this climate it occurs more often than a rainbow despite the number of rainy days we have.

Bright sundogs High and low sundogs Unusual sundogs
Cloud shapes and sundogs Sundog polarisation Contrail Sundogs
Changing sundogs Morning sundog Afternoon sundogs
Evening sundogs Miscellaneous sundogs Moondog

Other Halo Topics