Just a bit above the freezing point and pouring rain. The worst surface conditions I have ever experienced.

The trail was one long ribbon of ice. I mean, like, tractionless, glassy, smooth ice.
What a fun ride!
I didn't notice the ice at all with the studded tires. Once in a while I'd put a boot down to verify the surface, and it just slid along without any grip at all. I heard a lot of sirens and had to wait for an ambulance at one trail/road intersection.

Bad morning for a cage commute. I heard more sirens as I was coming in to Burlington, too.