Dandruff is a common condition that causes the skin on the scalp to flake. It isn't contagious or serious. But it can be embarrassing and difficult to treat. Dry skin is one of the most common causes of dandruff. And unfortunately, if this is the root of your dandruff, you might see it get worse this time of year.“If dry skin is causing your dandruff, it's easier to tell as other places of your body are most likely dry as well.