Weather was perfect for me - cool and overcast. I wore arm warmers most of the time. The sun came out around 3:00 for a little bit.
I've done this ride in the sweltering heat too, I much prefer the cool.

V - are you familiar with the Marshall-Petaluma Road? The metric century went up it from the east side this year -- looked at my Krebs map -- yikes! If I read it right it's about 1000 feet of climbing in 2+ miles.