Fair weather riders indeed. Below 70 is perfect for riding as far as I'm concerned, maybe even a bit cooler than that. I like upper 50's. Cool enough to keep you cool on a strenuous ride but warm enough that you don't have to wear long sleeves or full finger gloves.

I am blessed in my neck of the woods with good year round riding conditions. In the winter, unless it's actively raining (heavily), it's good fun to go out for a ride. High temps in the dead of winter will still usually get up into the mid-50's. No snow to worry about, just damp pavement and runoff from the hills to make a filthy mess of the bike if a big storm has rolled through recently.