This will be
#9 for me. In the early am, it can get a bit chilly. I usually depart w/ arm warmers and a vest. I'll carry a small lite athletic type of back pack that I'll throw all this into, including my lights & blinky. I usually stash it at the start of the Monitor climb. Other riders will do this too. Then after the lunch stop I'll pick it up and drop it off at my car whilst going thru Markleeville.
As for afternoon rainstorms, they can happen and they will pass. So you will get wet and might get chilled, but honestly, the weather is nice. They actually motivate me to ride harder and faster so I can beat them out. Good luck. Personally this year I'm hoping the fire will be out long enough to allow us to ride the route.
BR