Car costs $250/mo to park at work and a little bit for gas. Bike is free.
I'm actually colder in the car than on the bike, because the car doesn't warm up enough for heat, in my short trip to work. On the bike, I'm only cold for the first block or two, and I'm always in an energetic mood when I ride to work, vs yawning when I step out of the car.
The car is definitely drier. But on the bike I'm not actually wet - my face and raingear are wet, the rest of me is dry. Sometime people in the elevator ask me "aren't you soaked?" and I explain to them that I could stand in the shower, with all the gear I wear. I don't believe in "breathable" rain jackets; mine is flat-out water proof.
And my legs have never looked better, tee hee.
If I had a longer commute, say 10 miles, but still on city streets or with a bike path route, I'd look into a velomobile, which is an enclosed, pedaled trike. They have electric assists now that will scoot you to 25-30 mph for a limited time, you can't ride the battery the whole way, but if there is a dicey section of road where you need to be moving faster, or for a sharp hill, the boost is there.
Unfort they are stupid expensive.