Rain the past couple days and Chuck agreed to breakfast meeting in San Mateo. Had to work Saturdays with catalog breathing down my neck. So we set for an early 8am meal. Cloudy and cool at 7:10 as I roll the VFR out. Up 85 I wish I had heated vest and grips thinking this may be a bad idea. Mt View there is sun on 101. So I keep going. Up the peninsula I close in on whipple ave and I see a big white wall of fog. It was the thickest fog I ever got into! Everything was whiteout and all traffic slowed down to a crawl at about 25! My face shield was covered and I kept wiping it off and I flip it up and my glasses fog up. Put my right signal on and move over to exit at whipple. Really worried I would get hit from behind. Couldn't see anything but some small red brake lights. Got off the highway and parked at the corner gas station and waited for it to burn off. Called Chuck and he was at Baywatch already 7 miles north. Finally get there freezing cold and gulped my hot tea. Good conversation and the denver omelet. We rode up to 280 thru the hills and I went south for work.