My ride home yesterday was in the dark but it was about 45 degrees out. And no wind at all. That's a great temperature. Withing 2 minutes of starting you are warmed up and the air is the right temp to keep you from overheating without making you cold.
I ended up riding in and out of every side street to extend the ride
Now those 22 degree mornings this week have been rough. That's just cold. I'm cold when I start. I'm cold when I get there.
30 is usually my lower limit. I'll drive when colder. But the cold snuck up on me this week.