|Alcatraz, Mt. Tamalpais, Smog - San Francisco 2013|
Let's look at some smog! If there aren't any storms coming through (and there haven't been), the Bay Area during the fall and winter is subject to unhealthy, visually polluting smog.
Although I guess that I shouldn't be calling it "smog," since modern day smog has historically been a product mainly of automobiles. This stuff is a combination of a lot of things, apparently. So we have "Spare The Air" days when no wood burning is allowed.