Seattle clyde boy here, I commute from Seward Park to downtown Seattle via Beacon Avenue.

Average temperature per Garmin Connect: 2 degrees C (that includes the 17 degrees C when the thing was indoors, though). It was

My commuting ensemble:

MEC shorts and jersey, Smartwool midweight baselayer, softshell jacket and Mansfield 2 tights from Nashbar, (yes, that Nashbar. I know, the roadies roll their eyes, Jan Heine cries. It's all made in the same Third World factories by the same slave/prison labour from the same petrochemicals. Deal.) Gloves and shoe covers by Endura.

Result:

I was good and warm the whole way, actually had to unzip the jacket for the first half as I got on the climb up Myrtle Street and Beacon Ave. I'm glad the Rizal Bridge was sanded and iced. I looked to my right and saw a fresh layer of white frost on the pedestrian side of the bridge. I have learned from painful experience that that stuff is slicker than Slick Willard and you have a much greater than 47% chance of wrecking if you attempt to ride on it.

As of right now, I have a total of just under 100 commuting miles in this month, which is half of what I rode all of last month.