Every day when I cycle to work, I just plan that I'll eventually be rained on (which, in the NW, is a safe bet). Then, there's no surprise. I think it's important to realize that rain isn't bad, and being rained on isn't bad. It's no different than being "sunned" on really. Whether sweat or rain, you'll be getting wet one way or another. Unless it's cold, I wouldn't even worry about a rain jacket. Just wear cycling shorts and a breathable / water-wicking shirt (like a hiking / running shirt). When you get to work, shower down or towel off. You'll feel refreshed. FYI, fenders are worth it. It'll reduce direct spray on your neck, face and back. If it's really cold rain (less than 40 degrees F), then you may want to consider more protection (rain jacket, rain pants, etc).