According to a quick search, Seattle gets about 38 inches of rain across 155 days per year. That's a lot. I live in Memphis where it rains on about 107 days per year, but we get 57 inches of rain per year. In other words, it doesn't rain on as many days, but we still get a lot of rain here. When it rains, it really pours.

I'd say I'm pretty committed to riding in the rain, but two rainy conditions will keep me inside. First, I don't ride in active lightening. Second, I don't ride in blinding rain. Fortunately, my work hours are pretty flexible, so i can usually wait for a downpour to lighten up before heading out.