Storm Dragons are the masters of the skies. They are excellent fliers and land only to rest and eat. In addition, they have full control of the weather. They are very hot-tempered and easily angered. They will attack any human that bothers them, conjuring strong winds and dangerous lightning.

Dragons are highly-intelligent reptilian creatures that—from a human perspective, at least—appear to live forever. Many different varieties of dragon exist, each with their own unique qualities, habitats, and behavior. Adolescence in dragons is usually marked by the growth of a hatchling’s wings, although not all breeds of dragons grow wings and some breeds have other traits that indicate the beginning of maturation. In Galsreim, dragons and humans coexist peacefully.

Storm Diamond might be quick-tempered but he does not hold a grudge and he calms down quite quickly.  However, he does lead a stressful life because he takes his "weather controlling" duties very seriously.  He realizes—as other dragons don't—that you can't have days and days of wind and rain just because you enjoy them: there has to be sunshine sometimes.  So a great deal of his time is spent undoing what other dragons have done.