Weather pictures of the year 2011: lightning, auroras, snow and ice - Telegraph
Not every cloud has a silver lining; this multi-coloured cloud looks as if a rainbow has formed high in the heavens. The phenomenom - called a sundog - happens when ice crystals appear in clouds and refract the sun's rays. Photographer Robert Arn captured the cloud in Heyworth, Illinois, America. Picture: Robert Arn/solent
Sky Phenomena: Sun Dogs: "...an atmospheric phenomenon that creates bright spots of light in the sky, often on a luminous ring or halo on either side of the sun. Sundogs may appear as a colored patch of light to the left or right of the sun, 22° distant and at the same distance above the horizon as the sun, and in ice halos. They can be seen anywhere in the world during any season, but they are not always obvious or bright. Sundogs are best seen and are most conspicuous when the sun is low."