Originally Posted by Carbonfiberboy
Bare knees start at 50°-55° depending on sun. No booties in the rain start at about 60°, though many people never wear them. Bare fingers at about 50°.
That sounds about right to me. Temp at the start of Saturday's group ride was about 35, and I wore a base layer+jersey/full-fingered gloves/insulated tights and I was fine. Even skipped the booties, and I was surprised at what the other [more experienced] riders were wearing...jackets, balaclavas, booties. I was fine, but obviously everyone's different.
I never did reach my goal of a single-digit temps ride this year

The lowest I managed was 14F, though the wind was howling and the wind chill was below zero, so that has to count for something