A long commute in the rain is miserable. If it is relatively short, it's not so bad.

I have full fenders, but I don't wear rain gear. I know I'm going to be wet at the other end. Fortunately I have a shower and a means to dry my clothes for the ride home. But if I did not, then keeping some extra clothes at work and packing the wet ones on the way home would be the solution.

Shoes will get wet, even with full fenders, when it's a downpour, so shoe covers or waterproof boots will be advantageous. It's not as easy to dry shoes in nine hours.