[Inori]

If you swap out your Reds or Bones or whatever for some crappier bearings, skating in the rain is awesome. There's a bunch of tutorials on how to weatherproof decks and bearings, too, so you might want to check those out.

For your current situation, pop your bearings out, take off one of the covers (just put that side on the inside of the wheel when you're putting everything back together), clean out any dirt, and spray some WD40 in there (maybe grease it, too)

Edit: just remembered that Expedition One proofs most of their decks
Edit 2: bamboo longboards (Loaded and Arbor) are naturally watertight