It was 16 F this morning, 13 if you go by the National Weather Service numbers, the coldest I've yet biked in, and I managed to arrive sweaty. On the top half I wore a heavy sweater and mid-weight waxed cotton jacket over my regular street clothes, with a fleece scarf. On the bottom half I wore blue jeans and sneakers. On my head I had a thin wool cap with ear flaps under my helmet, which made me look profoundly silly. It did do just enough to cut the wind on my ears though, so they were fine. My light biking gloves were my only weak point; my fingers were cold, but not unbearably so. My commute is only about 3 miles, so I don't have to sweat the cold weather, as it were, too much, but then I tend to get warmer as I ride, including my hands, rather than colder.

Last night was slightly warmer, but I felt colder. Maybe it was lack of sun, and that the cotton jacket does a better job of cutting the wind than the wool coat I was wearing.

That may be, but it's what I wore,t-shirt and Oxford shirt under the sweater and jacket. I should probably look into something better, but I don't know about investing in a woolen base layer; I'm surviving so far without it.