Just for the year. Temps were in the low 40s today and the sun was shining. So I took a spin on the tiger. Got a bit of a scare; there was black ice on the road in the shaded corners. That may have been this year's last ride.
I always think about the angle of the sun when riding in winter shade. There are plenty of places in the hills around SF Bay that will not see direct sunlight until next May, So any damp-looking, shady pavement is suspect for ice if the air temps are below 40F. Bay Area temps have been below freezing several times over the last few weeks. I know that is still shorts weather for hardy upper-Midwest riders, but I'm busting out the heated jacket & gloves
Even in the Chicago Winter season I keep my 2008 Custom Bonnie 1100 ready for a potential ride when it gets above freezing and the roads are dry and clear of ice and snow. I have heated "FirstGear" gear that keeps my feet, hands and body plenty warm.
Still need to be careful even with temps a bit above freezing. Like kdharri mentioned, ice can be in shaded areas even if the temp is 39°.
I believe that is the temp that CHP parks their bikes for that reason.
@ fearless leader. A few folks here in Grand Rapids do the same thing...ride out in the winter when conditions allow. For me, I consider the presence of salt on the road an unacceptable riding condition - so I don't take my baby out until the salt has been washed off the roadways in the early spring. I have Gerbing gear for cold late fall/early spring days, but put the bike away once the salt trucks make their debut. When I lived up north (Houghton, MI) in college, I had a roommate who rode all winter. Temps were too low for salt to be effective, so they sand the roads instead...he had a Kaw 2 stroke enduro that handled those conditions great. Even if conditions allowed ice to form, it wasn't slippery with all that sand content...