Try simply drinking more water... And washing the dirt from you hands more often with milder soap. Or wearing gloves... Besides some protection from cuts and such, they cut down on wicking of moisture via dirt or air.
On top of just dry air in some climates this time of year - dirt from our line of work can wick moister out of your hands. That coupled with a few beers at night, and/or a few cups of coffee in the morning without backing it up with some water can do a number on you after a while.
