Surprise, here in Seattle we often ride in the rain!
we wear raincoats, booties, even head gear .. The stronger riders find that rainpants don't do them much good because they get just as wet from sweat inside them but for me they are a godsend because they keep me warm.

In rain, slow down. Make sure you glow (bright yellow) do everything you can dresswise to be seen.

and believe it or not, many of our club rides say "Rain cancels"
(this doesn't include major rides like chilly hilly, Seattle to Portland, etc)