Having moved from the UK to Seattle, US I have decided to try to live in the US without owning a car. I lived in the UK for almost 3 years without one and that worked out just fine; even lost 20-30 pounds in the process (weight, not money!). My bicycle commute is below; an 8.6 mi (13.8 km) trip each way. The first 1/3 of a mile or so is on a road, the rest of the distance is on bike lanes or bike paths, which makes it super-easy to get to work.
The wetness of Seattle weather in the winter is exaggerated. Commuting on a daily basis; 40-50 minutes each way (actual riding time depending on mood, wind and choice of bicycle) gets me wet approximately 30% of the time I spend on the road. I expect it to be less in the summer. So really, no big deal at all.