23F w/clear skies and a 12 mph north wind. Coldest ride to date! Very uneventful as there is little traffic on the roads. Not sure if lots of people are still on vacation or if it's because Oklahoma University students don't start classes until 1/17. No matter, I'll take what I can get. The cold drained the battery of my headlight to the point where it began to do its flash of "Hey, I'm running low on juice!" Never had that happen before. My e-bike's battery also loses about 40% of its power by the time I get to the office; during summer it would only lose 20%. I don't like the cold.