Sometimes the weather interferes with you being able to do your job. Sometimes you just need to take a break. Whenever we had a weather day, there was a prescribed order for the games we played. The ritual of moving through the same games, in the same order, as a team was a great morale boost when we were kept inside:
Obviously, those aren't the only free online games available, and no one is really bound to that order. Most of the distractions below offer daily puzzles to go back to, so be sure to bookmark the ones you love.
This is a site that provides many daily games, I tend to do the crosswords and circuits most often, sometimes memoku and poker hands.